xml.html revision 78fed53e2b295942b88764608081ba179d5e48cc
1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 2 "http://www.w3.org/TR/html4/loose.dtd"> 3<html> 4<head> 5 <title>The XML C parser and toolkit of Gnome</title> 6 <meta name="GENERATOR" content="amaya 5.1"> 7 <meta http-equiv="Content-Type" content="text/html"> 8</head> 9 10<body bgcolor="#ffffff"> 11<h1 align="center">The XML C parser and toolkit of Gnome</h1> 12 13<h1>Note: this is the flat content of the <a href="index.html">web 14site</a></h1> 15 16<h1 style="text-align: center">libxml, a.k.a. gnome-xml</h1> 17 18<p></p> 19 20<p 21style="text-align: right; font-style: italic; font-size: 10pt">"Programming 22with libxml2 is like the thrilling embrace of an exotic stranger." <a 23href="http://diveintomark.org/archives/2004/02/18/libxml2">Mark 24Pilgrim</a></p> 25 26<p>Libxml2 is the XML C parser and toolkit developed for the Gnome project 27(but usable outside of the Gnome platform), it is free software available 28under the <a href="http://www.opensource.org/licenses/mit-license.html">MIT 29License</a>. XML itself is a metalanguage to design markup languages, i.e. 30text language where semantic and structure are added to the content using 31extra "markup" information enclosed between angle brackets. HTML is the most 32well-known markup language. Though the library is written in C <a 33href="python.html">a variety of language bindings</a> make it available in 34other environments.</p> 35 36<p>Libxml2 is known to be very portable, the library should build and work 37without serious troubles on a variety of systems (Linux, Unix, Windows, 38CygWin, MacOS, MacOS X, RISC Os, OS/2, VMS, QNX, MVS, ...)</p> 39 40<p>Libxml2 implements a number of existing standards related to markup 41languages:</p> 42<ul> 43 <li>the XML standard: <a 44 href="http://www.w3.org/TR/REC-xml">http://www.w3.org/TR/REC-xml</a></li> 45 <li>Namespaces in XML: <a 46 href="http://www.w3.org/TR/REC-xml-names/">http://www.w3.org/TR/REC-xml-names/</a></li> 47 <li>XML Base: <a 48 href="http://www.w3.org/TR/xmlbase/">http://www.w3.org/TR/xmlbase/</a></li> 49 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc2396.txt">RFC 2396</a> : 50 Uniform Resource Identifiers <a 51 href="http://www.ietf.org/rfc/rfc2396.txt">http://www.ietf.org/rfc/rfc2396.txt</a></li> 52 <li>XML Path Language (XPath) 1.0: <a 53 href="http://www.w3.org/TR/xpath">http://www.w3.org/TR/xpath</a></li> 54 <li>HTML4 parser: <a 55 href="http://www.w3.org/TR/html401/">http://www.w3.org/TR/html401/</a></li> 56 <li>XML Pointer Language (XPointer) Version 1.0: <a 57 href="http://www.w3.org/TR/xptr">http://www.w3.org/TR/xptr</a></li> 58 <li>XML Inclusions (XInclude) Version 1.0: <a 59 href="http://www.w3.org/TR/xinclude/">http://www.w3.org/TR/xinclude/</a></li> 60 <li>ISO-8859-x encodings, as well as <a 61 href="http://www.cis.ohio-state.edu/rfc/rfc2044.txt">rfc2044</a> [UTF-8] 62 and <a href="http://www.cis.ohio-state.edu/rfc/rfc2781.txt">rfc2781</a> 63 [UTF-16] Unicode encodings, and more if using iconv support</li> 64 <li>part of SGML Open Technical Resolution TR9401:1997</li> 65 <li>XML Catalogs Working Draft 06 August 2001: <a 66 href="http://www.oasis-open.org/committees/entity/spec-2001-08-06.html">http://www.oasis-open.org/committees/entity/spec-2001-08-06.html</a></li> 67 <li>Canonical XML Version 1.0: <a 68 href="http://www.w3.org/TR/xml-c14n">http://www.w3.org/TR/xml-c14n</a> 69 and the Exclusive XML Canonicalization CR draft <a 70 href="http://www.w3.org/TR/xml-exc-c14n">http://www.w3.org/TR/xml-exc-c14n</a></li> 71 <li>Relax NG, ISO/IEC 19757-2:2003, <a 72 href="http://www.oasis-open.org/committees/relax-ng/spec-20011203.html">http://www.oasis-open.org/committees/relax-ng/spec-20011203.html</a></li> 73 <li>W3C XML Schemas Part 2: Datatypes <a 74 href="http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/">REC 02 May 75 2001</a></li> 76 <li>W3C <a href="http://www.w3.org/TR/xml-id/">xml:id</a> Working Draft 7 77 April 2004</li> 78</ul> 79 80<p>In most cases libxml2 tries to implement the specifications in a 81relatively strictly compliant way. As of release 2.4.16, libxml2 passed all 821800+ tests from the <a 83href="http://www.oasis-open.org/committees/xml-conformance/">OASIS XML Tests 84Suite</a>.</p> 85 86<p>To some extent libxml2 provides support for the following additional 87specifications but doesn't claim to implement them completely:</p> 88<ul> 89 <li>Document Object Model (DOM) <a 90 href="http://www.w3.org/TR/DOM-Level-2-Core/">http://www.w3.org/TR/DOM-Level-2-Core/</a> 91 the document model, but it doesn't implement the API itself, gdome2 does 92 this on top of libxml2</li> 93 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc959.txt">RFC 959</a> : 94 libxml2 implements a basic FTP client code</li> 95 <li><a href="http://www.cis.ohio-state.edu/rfc/rfc1945.txt">RFC 1945</a> : 96 HTTP/1.0, again a basic HTTP client code</li> 97 <li>SAX: a SAX2 like interface and a minimal SAX1 implementation compatible 98 with early expat versions</li> 99</ul> 100 101<p>A partial implementation of <a 102href="http://www.w3.org/TR/2001/REC-xmlschema-1-20010502/">XML Schemas Part 1031: Structure</a> is being worked on but it would be far too early to make any 104conformance statement about it at the moment.</p> 105 106<p>Separate documents:</p> 107<ul> 108 <li><a href="http://xmlsoft.org/XSLT/">the libxslt page</a> providing an 109 implementation of XSLT 1.0 and common extensions like EXSLT for 110 libxml2</li> 111 <li><a href="http://www.cs.unibo.it/~casarini/gdome2/">the gdome2 page</a> 112 : a standard DOM2 implementation for libxml2</li> 113 <li><a href="http://www.aleksey.com/xmlsec/">the XMLSec page</a>: an 114 implementation of <a href="http://www.w3.org/TR/xmldsig-core/">W3C XML 115 Digital Signature</a> for libxml2</li> 116 <li>also check the related links section below for more related and active 117 projects.</li> 118</ul> 119<!----------------<p>Results of the <a 120href="http://xmlbench.sourceforge.net/results/benchmark/index.html">xmlbench 121benchmark</a> on sourceforge February 2004 (smaller is better):</p> 122 123<p align="center"><img src="benchmark.png" 124alt="benchmark results for Expat Xerces libxml2 Oracle and Sun toolkits"></p> 125--------------> 126 127 128<p>Logo designed by <a href="mailto:liyanage@access.ch">Marc Liyanage</a>.</p> 129 130<h2><a name="Introducti">Introduction</a></h2> 131 132<p>This document describes libxml, the <a 133href="http://www.w3.org/XML/">XML</a> C parser and toolkit developed for the 134<a href="http://www.gnome.org/">Gnome</a> project. <a 135href="http://www.w3.org/XML/">XML is a standard</a> for building tag-based 136structured documents/data.</p> 137 138<p>Here are some key points about libxml:</p> 139<ul> 140 <li>Libxml2 exports Push (progressive) and Pull (blocking) type parser 141 interfaces for both XML and HTML.</li> 142 <li>Libxml2 can do DTD validation at parse time, using a parsed document 143 instance, or with an arbitrary DTD.</li> 144 <li>Libxml2 includes complete <a 145 href="http://www.w3.org/TR/xpath">XPath</a>, <a 146 href="http://www.w3.org/TR/xptr">XPointer</a> and <a 147 href="http://www.w3.org/TR/xinclude">XInclude</a> implementations.</li> 148 <li>It is written in plain C, making as few assumptions as possible, and 149 sticking closely to ANSI C/POSIX for easy embedding. Works on 150 Linux/Unix/Windows, ported to a number of other platforms.</li> 151 <li>Basic support for HTTP and FTP client allowing applications to fetch 152 remote resources.</li> 153 <li>The design is modular, most of the extensions can be compiled out.</li> 154 <li>The internal document representation is as close as possible to the <a 155 href="http://www.w3.org/DOM/">DOM</a> interfaces.</li> 156 <li>Libxml2 also has a <a 157 href="http://www.megginson.com/SAX/index.html">SAX like interface</a>; 158 the interface is designed to be compatible with <a 159 href="http://www.jclark.com/xml/expat.html">Expat</a>.</li> 160 <li>This library is released under the <a 161 href="http://www.opensource.org/licenses/mit-license.html">MIT 162 License</a>. See the Copyright file in the distribution for the precise 163 wording.</li> 164</ul> 165 166<p>Warning: unless you are forced to because your application links with a 167Gnome-1.X library requiring it, <strong><span 168style="background-color: #FF0000">Do Not Use libxml1</span></strong>, use 169libxml2</p> 170 171<h2><a name="FAQ">FAQ</a></h2> 172 173<p>Table of Contents:</p> 174<ul> 175 <li><a href="FAQ.html#License">License(s)</a></li> 176 <li><a href="FAQ.html#Installati">Installation</a></li> 177 <li><a href="FAQ.html#Compilatio">Compilation</a></li> 178 <li><a href="FAQ.html#Developer">Developer corner</a></li> 179</ul> 180 181<h3><a name="License">License</a>(s)</h3> 182<ol> 183 <li><em>Licensing Terms for libxml</em> 184 <p>libxml2 is released under the <a 185 href="http://www.opensource.org/licenses/mit-license.html">MIT 186 License</a>; see the file Copyright in the distribution for the precise 187 wording</p> 188 </li> 189 <li><em>Can I embed libxml2 in a proprietary application ?</em> 190 <p>Yes. The MIT License allows you to keep proprietary the changes you 191 made to libxml, but it would be graceful to send-back bug fixes and 192 improvements as patches for possible incorporation in the main 193 development tree.</p> 194 </li> 195</ol> 196 197<h3><a name="Installati">Installation</a></h3> 198<ol> 199 <li><strong><span style="background-color: #FF0000">Do Not Use 200 libxml1</span></strong>, use libxml2</li> 201 <li><em>Where can I get libxml</em> ? 202 <p>The original distribution comes from <a 203 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> or <a 204 href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.6/">gnome.org</a></p> 205 <p>Most Linux and BSD distributions include libxml, this is probably the 206 safer way for end-users to use libxml.</p> 207 <p>David Doolin provides precompiled Windows versions at <a 208 href="http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/ ">http://www.ce.berkeley.edu/~doolin/code/libxmlwin32/</a></p> 209 </li> 210 <li><em>I see libxml and libxml2 releases, which one should I install ?</em> 211 <ul> 212 <li>If you are not constrained by backward compatibility issues with 213 existing applications, install libxml2 only</li> 214 <li>If you are not doing development, you can safely install both. 215 Usually the packages <a 216 href="http://rpmfind.net/linux/RPM/libxml.html">libxml</a> and <a 217 href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a> are 218 compatible (this is not the case for development packages).</li> 219 <li>If you are a developer and your system provides separate packaging 220 for shared libraries and the development components, it is possible 221 to install libxml and libxml2, and also <a 222 href="http://rpmfind.net/linux/RPM/libxml-devel.html">libxml-devel</a> 223 and <a 224 href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a> 225 too for libxml2 >= 2.3.0</li> 226 <li>If you are developing a new application, please develop against 227 libxml2(-devel)</li> 228 </ul> 229 </li> 230 <li><em>I can't install the libxml package, it conflicts with libxml0</em> 231 <p>You probably have an old libxml0 package used to provide the shared 232 library for libxml.so.0, you can probably safely remove it. The libxml 233 packages provided on <a 234 href="ftp://rpmfind.net/pub/libxml/">rpmfind.net</a> provide 235 libxml.so.0</p> 236 </li> 237 <li><em>I can't install the libxml(2) RPM package due to failed 238 dependencies</em> 239 <p>The most generic solution is to re-fetch the latest src.rpm , and 240 rebuild it locally with</p> 241 <p><code>rpm --rebuild libxml(2)-xxx.src.rpm</code>.</p> 242 <p>If everything goes well it will generate two binary rpm packages (one 243 providing the shared libs and xmllint, and the other one, the -devel 244 package, providing includes, static libraries and scripts needed to build 245 applications with libxml(2)) that you can install locally.</p> 246 </li> 247</ol> 248 249<h3><a name="Compilatio">Compilation</a></h3> 250<ol> 251 <li><em>What is the process to compile libxml2 ?</em> 252 <p>As most UNIX libraries libxml2 follows the "standard":</p> 253 <p><code>gunzip -c xxx.tar.gz | tar xvf -</code></p> 254 <p><code>cd libxml-xxxx</code></p> 255 <p><code>/configure --help</code></p> 256 <p>to see the options, then the compilation/installation proper</p> 257 <p><code>/configure [possible options]</code></p> 258 <p><code>make</code></p> 259 <p><code>make install</code></p> 260 <p>At that point you may have to rerun ldconfig or a similar utility to 261 update your list of installed shared libs.</p> 262 </li> 263 <li><em>What other libraries are needed to compile/install libxml2 ?</em> 264 <p>Libxml2 does not require any other library, the normal C ANSI API 265 should be sufficient (please report any violation to this rule you may 266 find).</p> 267 <p>However if found at configuration time libxml2 will detect and use the 268 following libs:</p> 269 <ul> 270 <li><a href="http://www.info-zip.org/pub/infozip/zlib/">libz</a> : a 271 highly portable and available widely compression library.</li> 272 <li>iconv: a powerful character encoding conversion library. It is 273 included by default in recent glibc libraries, so it doesn't need to 274 be installed specifically on Linux. It now seems a <a 275 href="http://www.opennc.org/onlinepubs/7908799/xsh/iconv.html">part 276 of the official UNIX</a> specification. Here is one <a 277 href="http://www.gnu.org/software/libiconv/">implementation of the 278 library</a> which source can be found <a 279 href="ftp://ftp.ilog.fr/pub/Users/haible/gnu/">here</a>.</li> 280 </ul> 281 </li> 282 <li><em>Make check fails on some platforms</em> 283 <p>Sometimes the regression tests' results don't completely match the 284 value produced by the parser, and the makefile uses diff to print the 285 delta. On some platforms the diff return breaks the compilation process; 286 if the diff is small this is probably not a serious problem.</p> 287 <p>Sometimes (especially on Solaris) make checks fail due to limitations 288 in make. Try using GNU-make instead.</p> 289 </li> 290 <li><em>I use the CVS version and there is no configure script</em> 291 <p>The configure script (and other Makefiles) are generated. Use the 292 autogen.sh script to regenerate the configure script and Makefiles, 293 like:</p> 294 <p><code>/autogen.sh --prefix=/usr --disable-shared</code></p> 295 </li> 296 <li><em>I have troubles when running make tests with gcc-3.0</em> 297 <p>It seems the initial release of gcc-3.0 has a problem with the 298 optimizer which miscompiles the URI module. Please use another 299 compiler.</p> 300 </li> 301</ol> 302 303<h3><a name="Developer">Developer</a> corner</h3> 304<ol> 305 <li><em>Troubles compiling or linking programs using libxml2</em> 306 <p>Usually the problem comes from the fact that the compiler doesn't get 307 the right compilation or linking flags. There is a small shell script 308 <code>xml2-config</code> which is installed as part of libxml2 usual 309 install process which provides those flags. Use</p> 310 <p><code>xml2-config --cflags</code></p> 311 <p>to get the compilation flags and</p> 312 <p><code>xml2-config --libs</code></p> 313 <p>to get the linker flags. Usually this is done directly from the 314 Makefile as:</p> 315 <p><code>CFLAGS=`xml2-config --cflags`</code></p> 316 <p><code>LIBS=`xml2-config --libs`</code></p> 317 </li> 318 <li><em>xmlDocDump() generates output on one line.</em> 319 <p>Libxml2 will not <strong>invent</strong> spaces in the content of a 320 document since <strong>all spaces in the content of a document are 321 significant</strong>. If you build a tree from the API and want 322 indentation:</p> 323 <ol> 324 <li>the correct way is to generate those yourself too.</li> 325 <li>the dangerous way is to ask libxml2 to add those blanks to your 326 content <strong>modifying the content of your document in the 327 process</strong>. The result may not be what you expect. There is 328 <strong>NO</strong> way to guarantee that such a modification won't 329 affect other parts of the content of your document. See <a 330 href="http://xmlsoft.org/html/libxml-parser.html#xmlKeepBlanksDefault">xmlKeepBlanksDefault 331 ()</a> and <a 332 href="http://xmlsoft.org/html/libxml-tree.html#xmlSaveFormatFile">xmlSaveFormatFile 333 ()</a></li> 334 </ol> 335 </li> 336 <li>Extra nodes in the document: 337 <p><em>For a XML file as below:</em></p> 338 <pre><?xml version="1.0"?> 339<PLAN xmlns="http://www.argus.ca/autotest/1.0/"> 340<NODE CommFlag="0"/> 341<NODE CommFlag="1"/> 342</PLAN></pre> 343 <p><em>after parsing it with the function 344 pxmlDoc=xmlParseFile(...);</em></p> 345 <p><em>I want to the get the content of the first node (node with the 346 CommFlag="0")</em></p> 347 <p><em>so I did it as following;</em></p> 348 <pre>xmlNodePtr pnode; 349pnode=pxmlDoc->children->children;</pre> 350 <p><em>but it does not work. If I change it to</em></p> 351 <pre>pnode=pxmlDoc->children->children->next;</pre> 352 <p><em>then it works. Can someone explain it to me.</em></p> 353 <p></p> 354 <p>In XML all characters in the content of the document are significant 355 <strong>including blanks and formatting line breaks</strong>.</p> 356 <p>The extra nodes you are wondering about are just that, text nodes with 357 the formatting spaces which are part of the document but that people tend 358 to forget. There is a function <a 359 href="http://xmlsoft.org/html/libxml-parser.html">xmlKeepBlanksDefault 360 ()</a> to remove those at parse time, but that's an heuristic, and its 361 use should be limited to cases where you are certain there is no 362 mixed-content in the document.</p> 363 </li> 364 <li><em>I get compilation errors of existing code like when accessing 365 <strong>root</strong> or <strong>child fields</strong> of nodes.</em> 366 <p>You are compiling code developed for libxml version 1 and using a 367 libxml2 development environment. Either switch back to libxml v1 devel or 368 even better fix the code to compile with libxml2 (or both) by <a 369 href="upgrade.html">following the instructions</a>.</p> 370 </li> 371 <li><em>I get compilation errors about non existing 372 <strong>xmlRootNode</strong> or <strong>xmlChildrenNode</strong> 373 fields.</em> 374 <p>The source code you are using has been <a 375 href="upgrade.html">upgraded</a> to be able to compile with both libxml 376 and libxml2, but you need to install a more recent version: 377 libxml(-devel) >= 1.8.8 or libxml2(-devel) >= 2.1.0</p> 378 </li> 379 <li><em>XPath implementation looks seriously broken</em> 380 <p>XPath implementation prior to 2.3.0 was really incomplete. Upgrade to 381 a recent version, there are no known bugs in the current version.</p> 382 </li> 383 <li><em>The example provided in the web page does not compile.</em> 384 <p>It's hard to maintain the documentation in sync with the code 385 <grin/> ...</p> 386 <p>Check the previous points 1/ and 2/ raised before, and please send 387 patches.</p> 388 </li> 389 <li><em>Where can I get more examples and information than provided on the 390 web page?</em> 391 <p>Ideally a libxml2 book would be nice. I have no such plan ... But you 392 can:</p> 393 <ul> 394 <li>check more deeply the <a href="html/libxml-lib.html">existing 395 generated doc</a></li> 396 <li>have a look at <a href="examples/index.html">the set of 397 examples</a>.</li> 398 <li>look for examples of use for libxml2 function using the Gnome code. 399 For example the following will query the full Gnome CVS base for the 400 use of the <strong>xmlAddChild()</strong> function: 401 <p><a 402 href="http://cvs.gnome.org/lxr/search?string=xmlAddChild">http://cvs.gnome.org/lxr/search?string=xmlAddChild</a></p> 403 <p>This may be slow, a large hardware donation to the gnome project 404 could cure this :-)</p> 405 </li> 406 <li><a 407 href="http://cvs.gnome.org/bonsai/rview.cgi?cvsroot=/cvs/gnome&dir=gnome-xml">Browse 408 the libxml2 source</a> , I try to write code as clean and documented 409 as possible, so looking at it may be helpful. In particular the code 410 of xmllint.c and of the various testXXX.c test programs should 411 provide good examples of how to do things with the library.</li> 412 </ul> 413 </li> 414 <li>What about C++ ? 415 <p>libxml2 is written in pure C in order to allow easy reuse on a number 416 of platforms, including embedded systems. I don't intend to convert to 417 C++.</p> 418 <p>There is however a C++ wrapper which may fulfill your needs:</p> 419 <ul> 420 <li>by Ari Johnson <ari@btigate.com>: 421 <p>Website: <a 422 href="http://libxmlplusplus.sourceforge.net/">http://libxmlplusplus.sourceforge.net/</a></p> 423 <p>Download: <a 424 href="http://sourceforge.net/project/showfiles.php?group_id=12999">http://sourceforge.net/project/showfiles.php?group_id=12999</a></p> 425 </li> 426 <!-- Website is currently unavailable as of 2003-08-02 427 <li>by Peter Jones <pjones@pmade.org> 428 <p>Website: <a 429 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p> 430 </li> 431 --> 432 </ul> 433 </li> 434 <li>How to validate a document a posteriori ? 435 <p>It is possible to validate documents which had not been validated at 436 initial parsing time or documents which have been built from scratch 437 using the API. Use the <a 438 href="http://xmlsoft.org/html/libxml-valid.html#xmlValidateDtd">xmlValidateDtd()</a> 439 function. It is also possible to simply add a DTD to an existing 440 document:</p> 441 <pre>xmlDocPtr doc; /* your existing document */ 442xmlDtdPtr dtd = xmlParseDTD(NULL, filename_of_dtd); /* parse the DTD */ 443 444 dtd->name = xmlStrDup((xmlChar*)"root_name"); /* use the given root */ 445 446 doc->intSubset = dtd; 447 if (doc->children == NULL) xmlAddChild((xmlNodePtr)doc, (xmlNodePtr)dtd); 448 else xmlAddPrevSibling(doc->children, (xmlNodePtr)dtd); 449 </pre> 450 </li> 451 <li>So what is this funky "xmlChar" used all the time? 452 <p>It is a null terminated sequence of utf-8 characters. And only utf-8! 453 You need to convert strings encoded in different ways to utf-8 before 454 passing them to the API. This can be accomplished with the iconv library 455 for instance.</p> 456 </li> 457 <li>etc ...</li> 458</ol> 459 460<p></p> 461 462<h2><a name="Documentat">Developer Menu</a></h2> 463 464<p>There are several on-line resources related to using libxml:</p> 465<ol> 466 <li>Use the <a href="search.php">search engine</a> to look up 467 information.</li> 468 <li>Check the <a href="FAQ.html">FAQ.</a></li> 469 <li>Check the <a href="http://xmlsoft.org/html/libxml-lib.html">extensive 470 documentation</a> automatically extracted from code comments.</li> 471 <li>Look at the documentation about <a href="encoding.html">libxml 472 internationalization support</a>.</li> 473 <li>This page provides a global overview and <a href="example.html">some 474 examples</a> on how to use libxml.</li> 475 <li><a href="examples/index.html">Code examples</a></li> 476 <li>John Fleck's libxml2 tutorial: <a href="tutorial/index.html">html</a> 477 or <a href="tutorial/xmltutorial.pdf">pdf</a>.</li> 478 <li>If you need to parse large files, check the <a 479 href="xmlreader.html">xmlReader</a> API tutorial</li> 480 <li><a href="mailto:james@daa.com.au">James Henstridge</a> wrote <a 481 href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">some nice 482 documentation</a> explaining how to use the libxml SAX interface.</li> 483 <li>George Lebl wrote <a 484 href="http://www-106.ibm.com/developerworks/library/l-gnome3/">an article 485 for IBM developerWorks</a> about using libxml.</li> 486 <li>Check <a href="http://cvs.gnome.org/lxr/source/gnome-xml/TODO">the TODO 487 file</a>.</li> 488 <li>Read the <a href="upgrade.html">1.x to 2.x upgrade path</a> 489 description. If you are starting a new project using libxml you should 490 really use the 2.x version.</li> 491 <li>And don't forget to look at the <a 492 href="http://mail.gnome.org/archives/xml/">mailing-list archive</a>.</li> 493</ol> 494 495<h2><a name="Reporting">Reporting bugs and getting help</a></h2> 496 497<p>Well, bugs or missing features are always possible, and I will make a 498point of fixing them in a timely fashion. The best way to report a bug is to 499use the <a href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">Gnome 500bug tracking database</a> (make sure to use the "libxml2" module name). I 501look at reports there regularly and it's good to have a reminder when a bug 502is still open. Be sure to specify that the bug is for the package libxml2.</p> 503 504<p>For small problems you can try to get help on IRC, the #xml channel on 505irc.gnome.org (port 6667) usually have a few person subscribed which may help 506(but there is no garantee and if a real issue is raised it should go on the 507mailing-list for archival).</p> 508 509<p>There is also a mailing-list <a 510href="mailto:xml@gnome.org">xml@gnome.org</a> for libxml, with an <a 511href="http://mail.gnome.org/archives/xml/">on-line archive</a> (<a 512href="http://xmlsoft.org/messages">old</a>). To subscribe to this list, 513please visit the <a 514href="http://mail.gnome.org/mailman/listinfo/xml">associated Web</a> page and 515follow the instructions. <strong>Do not send code, I won't debug it</strong> 516(but patches are really appreciated!).</p> 517 518<p>Please note that with the current amount of virus and SPAM, sending mail 519to the list without being subscribed won't work. There is *far too many 520bounces* (in the order of a thousand a day !) I cannot approve them manually 521anymore. If your mail to the list bounced waiting for administrator approval, 522it is LOST ! Repost it and fix the problem triggering the error.</p> 523 524<p>Check the following <strong><span style="color: #FF0000">before 525posting</span></strong>:</p> 526<ul> 527 <li>Read the <a href="FAQ.html">FAQ</a> and <a href="search.php">use the 528 search engine</a> to get information related to your problem.</li> 529 <li>Make sure you are <a href="ftp://xmlsoft.org/">using a recent 530 version</a>, and that the problem still shows up in a recent version.</li> 531 <li>Check the <a href="http://mail.gnome.org/archives/xml/">list 532 archives</a> to see if the problem was reported already. In this case 533 there is probably a fix available, similarly check the <a 534 href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">registered 535 open bugs</a>.</li> 536 <li>Make sure you can reproduce the bug with xmllint or one of the test 537 programs found in source in the distribution.</li> 538 <li>Please send the command showing the error as well as the input (as an 539 attachment)</li> 540</ul> 541 542<p>Then send the bug with associated information to reproduce it to the <a 543href="mailto:xml@gnome.org">xml@gnome.org</a> list; if it's really libxml 544related I will approve it. Please do not send mail to me directly, it makes 545things really hard to track and in some cases I am not the best person to 546answer a given question, ask on the list.</p> 547 548<p>To <span style="color: #E50000">be really clear about support</span>:</p> 549<ul> 550 <li>Support or help <span style="color: #E50000">requests MUST be sent to 551 the list or on bugzilla</span> in case of problems, so that the Question 552 and Answers can be shared publicly. Failing to do so carries the implicit 553 message "I want free support but I don't want to share the benefits with 554 others" and is not welcome. I will automatically Carbon-Copy the 555 xml@gnome.org mailing list for any technical reply made about libxml2 or 556 libxslt.</li> 557 <li>There is <span style="color: #E50000">no garantee of support</span>, if 558 your question remains unanswered after a week, repost it, making sure you 559 gave all the detail needed and the information requested.</li> 560 <li>Failing to provide information as requested or double checking first 561 for prior feedback also carries the implicit message "the time of the 562 library maintainers is less valuable than my time" and might not be 563 welcome.</li> 564</ul> 565 566<p>Of course, bugs reported with a suggested patch for fixing them will 567probably be processed faster than those without.</p> 568 569<p>If you're looking for help, a quick look at <a 570href="http://mail.gnome.org/archives/xml/">the list archive</a> may actually 571provide the answer. I usually send source samples when answering libxml2 572usage questions. The <a 573href="http://xmlsoft.org/html/book1.html">auto-generated documentation</a> is 574not as polished as I would like (i need to learn more about DocBook), but 575it's a good starting point.</p> 576 577<h2><a name="help">How to help</a></h2> 578 579<p>You can help the project in various ways, the best thing to do first is to 580subscribe to the mailing-list as explained before, check the <a 581href="http://mail.gnome.org/archives/xml/">archives </a>and the <a 582href="http://bugzilla.gnome.org/buglist.cgi?product=libxml2">Gnome bug 583database</a>:</p> 584<ol> 585 <li>Provide patches when you find problems.</li> 586 <li>Provide the diffs when you port libxml2 to a new platform. They may not 587 be integrated in all cases but help pinpointing portability problems 588 and</li> 589 <li>Provide documentation fixes (either as patches to the code comments or 590 as HTML diffs).</li> 591 <li>Provide new documentations pieces (translations, examples, etc 592 ...).</li> 593 <li>Check the TODO file and try to close one of the items.</li> 594 <li>Take one of the points raised in the archive or the bug database and 595 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me 596 </a>before to avoid synchronization problems and check that the suggested 597 fix will fit in nicely :-)</li> 598</ol> 599 600<h2><a name="Downloads">Downloads</a></h2> 601 602<p>The latest versions of libxml2 can be found on the <a 603href="ftp://xmlsoft.org/">xmlsoft.org</a> server ( <a 604href="http://xmlsoft.org/sources/">HTTP</a>, <a 605href="ftp://xmlsoft.org/">FTP</a> and rsync are available), there is also 606mirrors (<a href="ftp://ftp.planetmirror.com/pub/xmlsoft/">Australia</a>( <a 607href="http://xmlsoft.planetmirror.com/">Web</a>), <a 608href="ftp://fr.rpmfind.net/pub/libxml/">France</a>) or on the <a 609href="ftp://ftp.gnome.org/pub/GNOME/MIRRORS.html">Gnome FTP server</a> as <a 610href="ftp://ftp.gnome.org/pub/GNOME/sources/libxml2/2.6/">source archive</a> 611, Antonin Sprinzl also provide <a href="ftp://gd.tuwien.ac.at/pub/libxml/">a 612mirror in Austria</a>. (NOTE that you need both the <a 613href="http://rpmfind.net/linux/RPM/libxml2.html">libxml(2)</a> and <a 614href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml(2)-devel</a> 615packages installed to compile applications using libxml.)</p> 616 617<p>You can find all the history of libxml(2) and libxslt releases in the <a 618href="http://xmlsoft.org/sources/old/">old</a> directory. The precompiled 619Windows binaries made by Igor Zlatovic are available in the <a 620href="http://xmlsoft.org/sources/win32/">win32</a> directory.</p> 621 622<p>Binary ports:</p> 623<ul> 624 <li>Red Hat RPMs for i386 are available directly on <a 625 href="ftp://xmlsoft.org/">xmlsoft.org</a>, the source RPM will compile on 626 any architecture supported by Red Hat.</li> 627 <li><a href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the 628 maintainer of the Windows port, <a 629 href="http://www.zlatkovic.com/projects/libxml/index.html">he provides 630 binaries</a>.</li> 631 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides 632 <a href="http://garypennington.net/libxml2/">Solaris binaries</a>.</li> 633 <li><a href="mailto:Steve.Ball@zveno.com">Steve Ball</a> provides <a 634 href="http://www.zveno.com/open_source/libxml2xslt.html">Mac Os X 635 binaries</a>.</li> 636 <li>The HP-UX porting center provides <a 637 href="http://hpux.connect.org.uk/hppd/hpux/Gnome/">HP-UX binaries</a></li> 638</ul> 639 640<p>If you know other supported binary ports, please <a 641href="http://veillard.com/">contact me</a>.</p> 642 643<p><a name="Snapshot">Snapshot:</a></p> 644<ul> 645 <li>Code from the W3C cvs base libxml2 module, updated hourly <a 646 href="ftp://xmlsoft.org/libxml2-cvs-snapshot.tar.gz">libxml2-cvs-snapshot.tar.gz</a>.</li> 647 <li>Docs, content of the web site, the list archive included <a 648 href="ftp://xmlsoft.org/libxml-docs.tar.gz">libxml-docs.tar.gz</a>.</li> 649</ul> 650 651<p><a name="Contribs">Contributions:</a></p> 652 653<p>I do accept external contributions, especially if compiling on another 654platform, get in touch with the list to upload the package, wrappers for 655various languages have been provided, and can be found in the <a 656href="python.html">bindings section</a></p> 657 658<p>Libxml2 is also available from CVS:</p> 659<ul> 660 <li><p>The <a href="http://cvs.gnome.org/viewcvs/libxml2/">Gnome CVS 661 base</a>. Check the <a 662 href="http://developer.gnome.org/tools/cvs.html">Gnome CVS Tools</a> 663 page; the CVS module is <b>libxml2</b>.</p> 664 </li> 665 <li>The <strong>libxslt</strong> module is also present there</li> 666</ul> 667 668<h2><a name="News">Releases</a></h2> 669 670<p>Items not finished and worked on, get in touch with the list if you want 671to help those</p> 672<ul> 673 <li>More testing on RelaxNG</li> 674 <li>Finishing up <a href="http://www.w3.org/TR/xmlschema-1/">XML 675 Schemas</a></li> 676</ul> 677 678<p>The <a href="ChangeLog.html">change log</a> describes the recents commits 679to the <a href="http://cvs.gnome.org/viewcvs/libxml2/">CVS</a> code base.</p> 680 681<p>There is the list of public releases:</p> 682 683<h3>2.6.14: Sep 29 2004</h3> 684<ul> 685 <li>build fixes: configure paths for xmllint and xsltproc, compilation 686 without HTML parser, compilation warning cleanups (William Brack & 687 Malcolm Tredinnick), VMS makefile update (Craig Berry), </li> 688 <li>bug fixes: xmlGetUTF8Char (William Brack), QName properties (Kasimier 689 Buchcik), XInclude testing, Notation serialization, UTF8ToISO8859x 690 transcoding (Mark Itzcovitz), lots of XML Schemas cleanup and fixes 691 (Kasimier), ChangeLog cleanup (Stepan Kasal), memory fixes (Mark Vakoc), 692 handling of failed realloc(), out of bound array adressing in Schemas 693 date handling, Python space/tabs cleanups (Malcolm Tredinnick), NMTOKENS 694 E20 validation fix (Malcolm), </li> 695 <li>improvements: added W3C XML Schemas testsuite (Kasimier Buchcik), add 696 xmlSchemaValidateOneElement (Kasimier), Python exception hierearchy 697 (Malcolm Tredinnick), Python libxml2 driver improvement (Malcolm 698 Tredinnick), Schemas support for xsi:schemaLocation, 699 xsi:noNamespaceSchemaLocation, xsi:type (Kasimier Buchcik)</li> 700</ul> 701 702<h3>2.6.13: Aug 31 2004</h3> 703<ul> 704 <li>build fixes: Windows and zlib (Igor Zlatkovic), -O flag with gcc, 705 Solaris compiler warning, fixing RPM BuildRequires,</li> 706 <li>fixes: DTD loading on Windows (Igor), Schemas error reports APIs 707 (Kasimier Buchcik), Schemas validation crash, xmlCheckUTF8 (William Brack 708 and Julius Mittenzwei), Schemas facet check (Kasimier), default namespace 709 problem (William), Schemas hexbinary empty values, encoding error could 710 genrate a serialization loop.</li> 711 <li>Improvements: Schemas validity improvements (Kasimier), added --path 712 and --load-trace options to xmllint</li> 713 <li>documentation: tutorial update (John Fleck)</li> 714</ul> 715 716<h3>2.6.12: Aug 22 2004</h3> 717<ul> 718 <li>build fixes: fix --with-minimum, elfgcchack.h fixes (Peter 719 Breitenlohner), perl path lookup (William), diff on Solaris (Albert 720 Chin), some 64bits cleanups.</li> 721 <li>Python: avoid a warning with 2.3 (William Brack), tab and space mixes 722 (William), wrapper generator fixes (William), Cygwin support (Gerrit P. 723 Haase), node wrapper fix (Marc-Antoine Parent), XML Schemas support 724 (Torkel Lyng)</li> 725 <li>Schemas: a lot of bug fixes and improvements from Kasimier Buchcik</li> 726 <li>fixes: RVT fixes (William), XPath context resets bug (William), memory 727 debug (Steve Hay), catalog white space handling (Peter Breitenlohner), 728 xmlReader state after attribute reading (William), structured error 729 handler (William), XInclude generated xml:base fixup (William), Windows 730 memory reallocation problem (Steve Hay), Out of Memory conditions 731 handling (William and Olivier Andrieu), htmlNewDoc() charset bug, 732 htmlReadMemory init (William), a posteriori validation DTD base 733 (William), notations serialization missing, xmlGetNodePath (Dodji), 734 xmlCheckUTF8 (Diego Tartara), missing line numbers on entity 735 (William)</li> 736 <li>improvements: DocBook catalog build scrip (William), xmlcatalog tool 737 (Albert Chin), xmllint --c14n option, no_proxy environment (Mike Hommey), 738 xmlParseInNodeContext() addition, extend xmllint --shell, allow XInclude 739 to not generate start/end nodes, extend xmllint --version to include CVS 740 tag (William)</li> 741 <li>documentation: web pages fixes, validity API docs fixes (William) 742 schemas API fix (Eric Haszlakiewicz), xmllint man page (John Fleck)</li> 743</ul> 744 745<h3>2.6.11: July 5 2004</h3> 746<ul> 747 <li>Schemas: a lot of changes and improvements by Kasimier Buchcik for 748 attributes, namespaces and simple types.</li> 749 <li>build fixes: --with-minimum (William Brack), some gcc cleanup 750 (William), --with-thread-alloc (William)</li> 751 <li>portability: Windows binary package change (Igor Zlatkovic), Catalog 752 path on Windows</li> 753 <li>documentation: update to the tutorial (John Fleck), xmllint return code 754 (John Fleck), man pages (Ville Skytta),</li> 755 <li>bug fixes: C14N bug serializing namespaces (Aleksey Sanin), testSAX 756 properly initialize the library (William), empty node set in XPath 757 (William), xmlSchemas errors (William), invalid charref problem pointed 758 by Morus Walter, XInclude xml:base generation (William), Relax-NG bug 759 with div processing (William), XPointer and xml:base problem(William), 760 Reader and entities, xmllint return code for schemas (William), reader 761 streaming problem (Steve Ball), DTD serialization problem (William), 762 libxml.m4 fixes (Mike Hommey), do not provide destructors as methods on 763 Python classes, xmlReader buffer bug, Python bindings memory interfaces 764 improvement (with St�phane Bidoul), Fixed the push parser to be back to 765 synchronous behaviour.</li> 766 <li>improvement: custom per-thread I/O enhancement (Rob Richards), register 767 namespace in debug shell (Stefano Debenedetti), Python based regression 768 test for non-Unix users (William), dynamically increase the number of 769 XPath extension functions in Python and fix a memory leak (Marc-Antoine 770 Parent and William)</li> 771 <li>performance: hack done with Arjan van de Ven to reduce ELF footprint 772 and generated code on Linux, plus use gcc runtime profiling to optimize 773 the code generated in the RPM packages.</li> 774</ul> 775 776<h3>2.6.10: May 17 2004</h3> 777<ul> 778 <li>Web page generated for ChangeLog</li> 779 <li>build fixes: --without-html problems, make check without make all</li> 780 <li>portability: problem with xpath.c on Windows (MSC and Borland), memcmp 781 vs. strncmp on Solaris, XPath tests on Windows (Mark Vakoc), C++ do not 782 use "list" as parameter name, make tests work with Python 1.5 (Ed 783 Davis),</li> 784 <li>improvements: made xmlTextReaderMode public, small buffers resizing 785 (Morten Welinder), add --maxmem option to xmllint, add 786 xmlPopInputCallback() for Matt Sergeant, refactoring of serialization 787 escaping, added escaping customization</li> 788 <li>bugfixes: xsd:extension (Taihei Goi), assorted regexp bugs (William 789 Brack), xmlReader end of stream problem, node deregistration with reader, 790 URI escaping and filemanes, XHTML1 formatting (Nick Wellnhofer), regexp 791 transition reduction (William), various XSD Schemas fixes (Kasimier 792 Buchcik), XInclude fallback problem (William), weird problems with DTD 793 (William), structured error handler callback context (William), reverse 794 xmlEncodeSpecialChars() behaviour back to escaping '"'</li> 795</ul> 796 797<h3>2.6.9: Apr 18 2004</h3> 798<ul> 799 <li>implement xml:id Working Draft, relaxed XPath id() checking</li> 800 <li>bugfixes: xmlCtxtReset (Brent Hendricks), line number and CDATA (Dave 801 Beckett), Relax-NG compilation (William Brack), Regexp patches (with 802 William), xmlUriEscape (Mark Vakoc), a Relax-NG notAllowed problem (with 803 William), Relax-NG name classes compares (William), XInclude duplicate 804 fallback (William), external DTD encoding detection (William), a DTD 805 validation bug (William), xmlReader Close() fix, recusive extention 806 schemas</li> 807 <li>improvements: use xmlRead* APIs in test tools (Mark Vakoc), indenting 808 save optimization, better handle IIS broken HTTP redirect behaviour (Ian 809 Hummel), HTML parser frameset (James Bursa), libxml2-python RPM 810 dependancy, XML Schemas union support (Kasimier Buchcik), warning removal 811 clanup (William), keep ChangeLog compressed when installing from RPMs</li> 812 <li>documentation: examples and xmlDocDumpMemory docs (John Fleck), new 813 example (load, xpath, modify, save), xmlCatalogDump() comments,</li> 814 <li>Windows: Borland C++ builder (Eric Zurcher), work around Microsoft 815 compiler NaN handling bug (Mark Vakoc)</li> 816</ul> 817 818<h3>2.6.8: Mar 23 2004</h3> 819<ul> 820 <li>First step of the cleanup of the serialization code and APIs</li> 821 <li>XML Schemas: mixed content (Adam Dickmeiss), QName handling fixes (Adam 822 Dickmeiss), anyURI for "" (John Belmonte)</li> 823 <li>Python: Canonicalization C14N support added (Anthony Carrico)</li> 824 <li>xmlDocCopyNode() extension (William)</li> 825 <li>Relax-NG: fix when processing XInclude results (William), external 826 reference in interleave (William), missing error on <choice> 827 failure (William), memory leak in schemas datatype facets.</li> 828 <li>xmlWriter: patch for better DTD support (Alfred Mickautsch)</li> 829 <li>bug fixes: xmlXPathLangFunction memory leak (Mike Hommey and William 830 Brack), no ID errors if using HTML_PARSE_NOERROR, xmlcatalog fallbacks to 831 URI on SYSTEM lookup failure, XInclude parse flags inheritance (William), 832 XInclude and XPointer fixes for entities (William), XML parser bug 833 reported by Holger Rauch, nanohttp fd leak (William), regexps char 834 groups '-' handling (William), dictionnary reference counting problems, 835 do not close stderr.</li> 836 <li>performance patches from Petr Pajas</li> 837 <li>Documentation fixes: XML_CATALOG_FILES in man pages (Mike Hommey)</li> 838 <li>compilation and portability fixes: --without-valid, catalog cleanups 839 (Peter Breitenlohner), MingW patch (Roland Schwingel), cross-compilation 840 to Windows (Christophe de Vienne), --with-html-dir fixup (Julio Merino 841 Vidal), Windows build (Eric Zurcher)</li> 842</ul> 843 844<h3>2.6.7: Feb 23 2004</h3> 845<ul> 846 <li>documentation: tutorial updates (John Fleck), benchmark results</li> 847 <li>xmlWriter: updates and fixes (Alfred Mickautsch, Lucas Brasilino)</li> 848 <li>XPath optimization (Petr Pajas)</li> 849 <li>DTD ID handling optimization</li> 850 <li>bugfixes: xpath number with > 19 fractional (William Brack), push 851 mode with unescaped '>' characters, fix xmllint --stream --timing, fix 852 xmllint --memory --stream memory usage, xmlAttrSerializeTxtContent 853 handling NULL, trying to fix Relax-NG/Perl interface.</li> 854 <li>python: 2.3 compatibility, whitespace fixes (Malcolm Tredinnick)</li> 855 <li>Added relaxng option to xmllint --shell</li> 856</ul> 857 858<h3>2.6.6: Feb 12 2004</h3> 859<ul> 860 <li>nanohttp and nanoftp: buffer overflow error on URI parsing (Igor and 861 William) reported by Yuuichi Teranishi</li> 862 <li>bugfixes: make test and path issues, xmlWriter attribute serialization 863 (William Brack), xmlWriter indentation (William), schemas validation 864 (Eric Haszlakiewicz), XInclude dictionnaries issues (William and Oleg 865 Paraschenko), XInclude empty fallback (William), HTML warnings (William), 866 XPointer in XInclude (William), Python namespace serialization, 867 isolat1ToUTF8 bound error (Alfred Mickautsch), output of parameter 868 entities in internal subset (William), internal subset bug in push mode, 869 <xs:all> fix (Alexey Sarytchev)</li> 870 <li>Build: fix for automake-1.8 (Alexander Winston), warnings removal 871 (Philip Ludlam), SOCKLEN_T detection fixes (Daniel Richard), fix 872 --with-minimum configuration.</li> 873 <li>XInclude: allow the 2001 namespace without warning.</li> 874 <li>Documentation: missing example/index.html (John Fleck), version 875 dependancies (John Fleck)</li> 876 <li>reader API: structured error reporting (Steve Ball)</li> 877 <li>Windows compilation: mingw, msys (Mikhail Grushinskiy), function 878 prototype (Cameron Johnson), MSVC6 compiler warnings, _WINSOCKAPI_ 879 patch</li> 880 <li>Parsers: added xmlByteConsumed(ctxt) API to get the byte offest in 881 input.</li> 882</ul> 883 884<h3>2.6.5: Jan 25 2004</h3> 885<ul> 886 <li>Bugfixes: dictionnaries for schemas (William Brack), regexp segfault 887 (William), xs:all problem (William), a number of XPointer bugfixes 888 (William), xmllint error go to stderr, DTD validation problem with 889 namespace, memory leak (William), SAX1 cleanup and minimal options fixes 890 (Mark Vadoc), parser context reset on error (Shaun McCance), XPath union 891 evaluation problem (William) , xmlReallocLoc with NULL (Aleksey Sanin), 892 XML Schemas double free (Steve Ball), XInclude with no href, argument 893 callbacks order for XPath callbacks (Frederic Peters)</li> 894 <li>Documentation: python scripts (William Brack), xslt stylesheets (John 895 Fleck), doc (Sven Zimmerman), I/O example.</li> 896 <li>Python bindings: fixes (William), enum support (St�phane Bidoul), 897 structured error reporting (St�phane Bidoul)</li> 898 <li>XInclude: various fixes for conformance, problem related to dictionnary 899 references (William & me), recursion (William)</li> 900 <li>xmlWriter: indentation (Lucas Brasilino), memory leaks (Alfred 901 Mickautsch),</li> 902 <li>xmlSchemas: normalizedString datatype (John Belmonte)</li> 903 <li>code cleanup for strings functions (William)</li> 904 <li>Windows: compiler patches (Mark Vakoc)</li> 905 <li>Parser optimizations, a few new XPath and dictionnary APIs for future 906 XSLT optimizations.</li> 907</ul> 908 909<h3>2.6.4: Dec 24 2003</h3> 910<ul> 911 <li>Windows build fixes (Igor Zlatkovic)</li> 912 <li>Some serious XInclude problems reported by Oleg Paraschenko and</li> 913 <li>Unix and Makefile packaging fixes (me, William Brack,</li> 914 <li>Documentation improvements (John Fleck, William Brack), example fix 915 (Lucas Brasilino)</li> 916 <li>bugfixes: xmlTextReaderExpand() with xmlReaderWalker, XPath handling of 917 NULL strings (William Brack) , API building reader or parser from 918 filedescriptor should not close it, changed XPath sorting to be stable 919 again (William Brack), xmlGetNodePath() generating '(null)' (William 920 Brack), DTD validation and namespace bug (William Brack), XML Schemas 921 double inclusion behaviour</li> 922</ul> 923 924<h3>2.6.3: Dec 10 2003</h3> 925<ul> 926 <li>documentation updates and cleanup (DV, William Brack, John Fleck)</li> 927 <li>added a repository of examples, examples from Aleksey Sanin, Dodji 928 Seketeli, Alfred Mickautsch</li> 929 <li>Windows updates: Mark Vakoc, Igor Zlatkovic, Eric Zurcher, Mingw 930 (Kenneth Haley)</li> 931 <li>Unicode range checking (William Brack)</li> 932 <li>code cleanup (William Brack)</li> 933 <li>Python bindings: doc (John Fleck), bug fixes</li> 934 <li>UTF-16 cleanup and BOM issues (William Brack)</li> 935 <li>bug fixes: ID and xmlReader validation, XPath (William Brack), 936 xmlWriter (Alfred Mickautsch), hash.h inclusion problem, HTML parser 937 (James Bursa), attribute defaulting and validation, some serialization 938 cleanups, XML_GET_LINE macro, memory debug when using threads (William 939 Brack), serialization of attributes and entities content, xmlWriter 940 (Daniel Schulman)</li> 941 <li>XInclude bugfix, new APIs and update to the last version including the 942 namespace change.</li> 943 <li>XML Schemas improvements: include (Robert Stepanek), import and 944 namespace handling, fixed the regression tests troubles, added examples 945 based on Eric van der Vlist book, regexp fixes</li> 946 <li>preliminary pattern support for streaming (needed for schemas 947 constraints), added xmlTextReaderPreservePattern() to collect subdocument 948 when streaming.</li> 949 <li>various fixes in the structured error handling</li> 950</ul> 951 952<h3>2.6.2: Nov 4 2003</h3> 953<ul> 954 <li>XPath context unregistration fixes</li> 955 <li>text node coalescing fixes (Mark Lilback)</li> 956 <li>API to screate a W3C Schemas from an existing document (Steve Ball)</li> 957 <li>BeOS patches (Marcin 'Shard' Konicki)</li> 958 <li>xmlStrVPrintf function added (Aleksey Sanin)</li> 959 <li>compilation fixes (Mark Vakoc)</li> 960 <li>stdin parsing fix (William Brack)</li> 961 <li>a posteriori DTD validation fixes</li> 962 <li>xmlReader bug fixes: Walker fixes, python bindings</li> 963 <li>fixed xmlStopParser() to really stop the parser and errors</li> 964 <li>always generate line numbers when using the new xmlReadxxx 965 functions</li> 966 <li>added XInclude support to the xmlReader interface</li> 967 <li>implemented XML_PARSE_NONET parser option</li> 968 <li>DocBook XSLT processing bug fixed</li> 969 <li>HTML serialization for <p> elements (William Brack and me)</li> 970 <li>XPointer failure in XInclude are now handled as resource errors</li> 971 <li>fixed xmllint --html to use the HTML serializer on output (added 972 --xmlout to implement the previous behaviour of saving it using the XML 973 serializer)</li> 974</ul> 975 976<h3>2.6.1: Oct 28 2003</h3> 977<ul> 978 <li>Mostly bugfixes after the big 2.6.0 changes</li> 979 <li>Unix compilation patches: libxml.m4 (Patrick Welche), warnings cleanup 980 (William Brack)</li> 981 <li>Windows compilation patches (Joachim Bauch, Stephane Bidoul, Igor 982 Zlatkovic)</li> 983 <li>xmlWriter bugfix (Alfred Mickautsch)</li> 984 <li>chvalid.[ch]: couple of fixes from Stephane Bidoul</li> 985 <li>context reset: error state reset, push parser reset (Graham 986 Bennett)</li> 987 <li>context reuse: generate errors if file is not readable</li> 988 <li>defaulted attributes for element coming from internal entities 989 (Stephane Bidoul)</li> 990 <li>Python: tab and spaces mix (William Brack)</li> 991 <li>Error handler could crash in DTD validation in 2.6.0</li> 992 <li>xmlReader: do not use the document or element _private field</li> 993 <li>testSAX.c: avoid a problem with some PIs (Massimo Morara)</li> 994 <li>general bug fixes: mandatory encoding in text decl, serializing 995 Document Fragment nodes, xmlSearchNs 2.6.0 problem (Kasimier Buchcik), 996 XPath errors not reported, slow HTML parsing of large documents.</li> 997</ul> 998 999<h3>2.6.0: Oct 20 2003</h3> 1000<ul> 1001 <li>Major revision release: should be API and ABI compatible but got a lot 1002 of change</li> 1003 <li>Increased the library modularity, far more options can be stripped out, 1004 a --with-minimum configuration will weight around 160KBytes</li> 1005 <li>Use per parser and per document dictionnary, allocate names and small 1006 text nodes from the dictionnary</li> 1007 <li>Switch to a SAX2 like parser rewrote most of the XML parser core, 1008 provides namespace resolution and defaulted attributes, minimize memory 1009 allocations and copies, namespace checking and specific error handling, 1010 immutable buffers, make predefined entities static structures, etc...</li> 1011 <li>rewrote all the error handling in the library, all errors can be 1012 intercepted at a structured level, with precise information 1013 available.</li> 1014 <li>New simpler and more generic XML and HTML parser APIs, allowing to 1015 easilly modify the parsing options and reuse parser context for multiple 1016 consecutive documents.</li> 1017 <li>Similar new APIs for the xmlReader, for options and reuse, provided new 1018 functions to access content as const strings, use them for Python 1019 bindings</li> 1020 <li>a lot of other smaller API improvements: xmlStrPrintf (Aleksey Sanin), 1021 Walker i.e. reader on a document tree based on Alfred Mickautsch code, 1022 make room in nodes for line numbers, reference counting and future PSVI 1023 extensions, generation of character ranges to be checked with faster 1024 algorithm (William), xmlParserMaxDepth (Crutcher Dunnavant), buffer 1025 access</li> 1026 <li>New xmlWriter API provided by Alfred Mickautsch</li> 1027 <li>Schemas: base64 support by Anthony Carrico</li> 1028 <li>Parser<->HTTP integration fix, proper processing of the Mime-Type 1029 and charset informations if available.</li> 1030 <li>Relax-NG: bug fixes including the one reported by Martijn Faassen and 1031 zeroOrMore, better error reporting.</li> 1032 <li>Python bindings (St�phane Bidoul), never use stdout for errors 1033 output</li> 1034 <li>Portability: all the headers have macros for export and calling 1035 convention definitions (Igor Zlatkovic), VMS update (Craig A. Berry), 1036 Windows: threads (Jesse Pelton), Borland compiler (Eric Zurcher, Igor), 1037 Mingw (Igor), typos (Mark Vakoc), beta version (Stephane Bidoul), 1038 warning cleanups on AIX and MIPS compilers (William Brack), BeOS (Marcin 1039 'Shard' Konicki)</li> 1040 <li>Documentation fixes and README (William Brack), search fix (William), 1041 tutorial updates (John Fleck), namespace docs (Stefan Kost)</li> 1042 <li>Bug fixes: xmlCleanupParser (Dave Beckett), threading uninitialized 1043 mutexes, HTML doctype lowercase, SAX/IO (William), compression detection 1044 and restore (William), attribute declaration in DTDs (William), namespace 1045 on attribute in HTML output (William), input filename (Rob Richards), 1046 namespace DTD validation, xmlReplaceNode (Chris Ryland), I/O callbacks 1047 (Markus Keim), CDATA serialization (Shaun McCance), xmlReader (Peter 1048 Derr), high codepoint charref like &#x10FFFF;, buffer access in push 1049 mode (Justin Fletcher), TLS threads on Windows (Jesse Pelton), XPath bug 1050 (William), xmlCleanupParser (Marc Liyanage), CDATA output (William), HTTP 1051 error handling.</li> 1052 <li>xmllint options: --dtdvalidfpi for Tobias Reif, --sax1 for compat 1053 testing, --nodict for building without tree dictionnary, --nocdata to 1054 replace CDATA by text, --nsclean to remove surperfluous namespace 1055 declarations</li> 1056 <li>added xml2-config --libtool-libs option from Kevin P. Fleming</li> 1057 <li>a lot of profiling and tuning of the code, speedup patch for 1058 xmlSearchNs() by Luca Padovani. The xmlReader should do far less 1059 allocation and it speed should get closer to SAX. Chris Anderson worked 1060 on speeding and cleaning up repetitive checking code.</li> 1061 <li>cleanup of "make tests"</li> 1062 <li>libxml-2.0-uninstalled.pc from Malcolm Tredinnick</li> 1063 <li>deactivated the broken docBook SGML parser code and plugged the XML 1064 parser instead.</li> 1065</ul> 1066 1067<h3>2.5.11: Sep 9 2003</h3> 1068 1069<p>A bugfix only release:</p> 1070<ul> 1071 <li>risk of crash in Relax-NG</li> 1072 <li>risk of crash when using multithreaded programs</li> 1073</ul> 1074 1075<h3>2.5.10: Aug 15 2003</h3> 1076 1077<p>A bugfixes only release</p> 1078<ul> 1079 <li>Windows Makefiles (William Brack)</li> 1080 <li>UTF-16 support fixes (Mark Itzcovitz)</li> 1081 <li>Makefile and portability (William Brack) automake, Linux alpha, Mingw 1082 on Windows (Mikhail Grushinskiy)</li> 1083 <li>HTML parser (Oliver Stoeneberg)</li> 1084 <li>XInclude performance problem reported by Kevin Ruscoe</li> 1085 <li>XML parser performance problem reported by Grant Goodale</li> 1086 <li>xmlSAXParseDTD() bug fix from Malcolm Tredinnick</li> 1087 <li>and a couple other cleanup</li> 1088</ul> 1089 1090<h3>2.5.9: Aug 9 2003</h3> 1091<ul> 1092 <li>bugfixes: IPv6 portability, xmlHasNsProp (Markus Keim), Windows build 1093 (Wiliam Brake, Jesse Pelton, Igor), Schemas (Peter Sobisch), threading 1094 (Rob Richards), hexBinary type (), UTF-16 BOM (Dodji Seketeli), 1095 xmlReader, Relax-NG schemas compilation, namespace handling, EXSLT (Sean 1096 Griffin), HTML parsing problem (William Brack), DTD validation for mixed 1097 content + namespaces, HTML serialization, library initialization, 1098 progressive HTML parser</li> 1099 <li>better interfaces for Relax-NG error handling (Joachim Bauch, )</li> 1100 <li>adding xmlXIncludeProcessTree() for XInclud'ing in a subtree</li> 1101 <li>doc fixes and improvements (John Fleck)</li> 1102 <li>configure flag for -with-fexceptions when embedding in C++</li> 1103 <li>couple of new UTF-8 helper functions (William Brack)</li> 1104 <li>general encoding cleanup + ISO-8859-x without iconv (Peter Jacobi)</li> 1105 <li>xmlTextReader cleanup + enum for node types (Bjorn Reese)</li> 1106 <li>general compilation/warning cleanup Solaris/HP-UX/... (William 1107 Brack)</li> 1108</ul> 1109 1110<h3>2.5.8: Jul 6 2003</h3> 1111<ul> 1112 <li>bugfixes: XPath, XInclude, file/URI mapping, UTF-16 save (Mark 1113 Itzcovitz), UTF-8 checking, URI saving, error printing (William Brack), 1114 PI related memleak, compilation without schemas or without xpath (Joerg 1115 Schmitz-Linneweber/Garry Pennington), xmlUnlinkNode problem with DTDs, 1116 rpm problem on , i86_64, removed a few compilation problems from 2.5.7, 1117 xmlIOParseDTD, and xmlSAXParseDTD (Malcolm Tredinnick)</li> 1118 <li>portability: DJGPP (MsDos) , OpenVMS (Craig A. Berry)</li> 1119 <li>William Brack fixed multithreading lock problems</li> 1120 <li>IPv6 patch for FTP and HTTP accesses (Archana Shah/Wipro)</li> 1121 <li>Windows fixes (Igor Zlatkovic, Eric Zurcher), threading (St�phane 1122 Bidoul)</li> 1123 <li>A few W3C Schemas Structure improvements</li> 1124 <li>W3C Schemas Datatype improvements (Charlie Bozeman)</li> 1125 <li>Python bindings for thread globals (St�phane Bidoul), and method/class 1126 generator</li> 1127 <li>added --nonet option to xmllint</li> 1128 <li>documentation improvements (John Fleck)</li> 1129</ul> 1130 1131<h3>2.5.7: Apr 25 2003</h3> 1132<ul> 1133 <li>Relax-NG: Compiling to regexp and streaming validation on top of the 1134 xmlReader interface, added to xmllint --stream</li> 1135 <li>xmlReader: Expand(), Next() and DOM access glue, bug fixes</li> 1136 <li>Support for large files: RGN validated a 4.5GB instance</li> 1137 <li>Thread support is now configured in by default</li> 1138 <li>Fixes: update of the Trio code (Bjorn), WXS Date and Duration fixes 1139 (Charles Bozeman), DTD and namespaces (Brent Hendricks), HTML push parser 1140 and zero bytes handling, some missing Windows file path conversions, 1141 behaviour of the parser and validator in the presence of "out of memory" 1142 error conditions</li> 1143 <li>extended the API to be able to plug a garbage collecting memory 1144 allocator, added xmlMallocAtomic() and modified the allocations 1145 accordingly.</li> 1146 <li>Performances: removed excessive malloc() calls, speedup of the push and 1147 xmlReader interfaces, removed excessive thread locking</li> 1148 <li>Documentation: man page (John Fleck), xmlReader documentation</li> 1149 <li>Python: adding binding for xmlCatalogAddLocal (Brent M Hendricks)</li> 1150</ul> 1151 1152<h3>2.5.6: Apr 1 2003</h3> 1153<ul> 1154 <li>Fixed W3C XML Schemas datatype, should be compliant now except for 1155 binHex and base64 which are not supported yet.</li> 1156 <li>bug fixes: non-ASCII IDs, HTML output, XInclude on large docs and 1157 XInclude entities handling, encoding detection on external subsets, XML 1158 Schemas bugs and memory leaks, HTML parser (James Bursa)</li> 1159 <li>portability: python/trio (Albert Chin), Sun compiler warnings</li> 1160 <li>documentation: added --relaxng option to xmllint man page (John)</li> 1161 <li>improved error reporting: xml:space, start/end tag mismatches, Relax NG 1162 errors</li> 1163</ul> 1164 1165<h3>2.5.5: Mar 24 2003</h3> 1166<ul> 1167 <li>Lot of fixes on the Relax NG implementation. More testing including 1168 DocBook and TEI examples.</li> 1169 <li>Increased the support for W3C XML Schemas datatype</li> 1170 <li>Several bug fixes in the URI handling layer</li> 1171 <li>Bug fixes: HTML parser, xmlReader, DTD validation, XPath, encoding 1172 conversion, line counting in the parser.</li> 1173 <li>Added support for $XMLLINT_INDENT environment variable, FTP delete</li> 1174 <li>Fixed the RPM spec file name</li> 1175</ul> 1176 1177<h3>2.5.4: Feb 20 2003</h3> 1178<ul> 1179 <li>Conformance testing and lot of fixes on Relax NG and XInclude 1180 implementation</li> 1181 <li>Implementation of XPointer element() scheme</li> 1182 <li>Bug fixes: XML parser, XInclude entities merge, validity checking on 1183 namespaces, 1184 <p>2 serialization bugs, node info generation problems, a DTD regexp 1185 generation problem.</p> 1186 </li> 1187 <li>Portability: windows updates and path canonicalization (Igor)</li> 1188 <li>A few typo fixes (Kjartan Maraas)</li> 1189 <li>Python bindings generator fixes (Stephane Bidoul)</li> 1190</ul> 1191 1192<h3>2.5.3: Feb 10 2003</h3> 1193<ul> 1194 <li>RelaxNG and XML Schemas datatypes improvements, and added a first 1195 version of RelaxNG Python bindings</li> 1196 <li>Fixes: XLink (Sean Chittenden), XInclude (Sean Chittenden), API fix for 1197 serializing namespace nodes, encoding conversion bug, XHTML1 1198 serialization</li> 1199 <li>Portability fixes: Windows (Igor), AMD 64bits RPM spec file</li> 1200</ul> 1201 1202<h3>2.5.2: Feb 5 2003</h3> 1203<ul> 1204 <li>First implementation of RelaxNG, added --relaxng flag to xmllint</li> 1205 <li>Schemas support now compiled in by default.</li> 1206 <li>Bug fixes: DTD validation, namespace checking, XInclude and entities, 1207 delegateURI in XML Catalogs, HTML parser, XML reader (St�phane Bidoul), 1208 XPath parser and evaluation, UTF8ToUTF8 serialization, XML reader memory 1209 consumption, HTML parser, HTML serialization in the presence of 1210 namespaces</li> 1211 <li>added an HTML API to check elements and attributes.</li> 1212 <li>Documentation improvement, PDF for the tutorial (John Fleck), doc 1213 patches (Stefan Kost)</li> 1214 <li>Portability fixes: NetBSD (Julio Merino), Windows (Igor Zlatkovic)</li> 1215 <li>Added python bindings for XPointer, contextual error reporting 1216 (St�phane Bidoul)</li> 1217 <li>URI/file escaping problems (Stefano Zacchiroli)</li> 1218</ul> 1219 1220<h3>2.5.1: Jan 8 2003</h3> 1221<ul> 1222 <li>Fixes a memory leak and configuration/compilation problems in 2.5.0</li> 1223 <li>documentation updates (John)</li> 1224 <li>a couple of XmlTextReader fixes</li> 1225</ul> 1226 1227<h3>2.5.0: Jan 6 2003</h3> 1228<ul> 1229 <li>New <a href="xmlreader.html">XmltextReader interface</a> based on C# 1230 API (with help of St�phane Bidoul)</li> 1231 <li>Windows: more exports, including the new API (Igor)</li> 1232 <li>XInclude fallback fix</li> 1233 <li>Python: bindings for the new API, packaging (St�phane Bidoul), 1234 drv_libxml2.py Python xml.sax driver (St�phane Bidoul), fixes, speedup 1235 and iterators for Python-2.2 (Hannu Krosing)</li> 1236 <li>Tutorial fixes (john Fleck and Niraj Tolia) xmllint man update 1237 (John)</li> 1238 <li>Fix an XML parser bug raised by Vyacheslav Pindyura</li> 1239 <li>Fix for VMS serialization (Nigel Hall) and config (Craig A. Berry)</li> 1240 <li>Entities handling fixes</li> 1241 <li>new API to optionally track node creation and deletion (Lukas 1242 Schroeder)</li> 1243 <li>Added documentation for the XmltextReader interface and some <a 1244 href="guidelines.html">XML guidelines</a></li> 1245</ul> 1246 1247<h3>2.4.30: Dec 12 2002</h3> 1248<ul> 1249 <li>2.4.29 broke the python bindings, rereleasing</li> 1250 <li>Improvement/fixes of the XML API generator, and couple of minor code 1251 fixes.</li> 1252</ul> 1253 1254<h3>2.4.29: Dec 11 2002</h3> 1255<ul> 1256 <li>Windows fixes (Igor): Windows CE port, pthread linking, python bindings 1257 (St�phane Bidoul), Mingw (Magnus Henoch), and export list updates</li> 1258 <li>Fix for prev in python bindings (ERDI Gergo)</li> 1259 <li>Fix for entities handling (Marcus Clarke)</li> 1260 <li>Refactored the XML and HTML dumps to a single code path, fixed XHTML1 1261 dump</li> 1262 <li>Fix for URI parsing when handling URNs with fragment identifiers</li> 1263 <li>Fix for HTTP URL escaping problem</li> 1264 <li>added an TextXmlReader (C#) like API (work in progress)</li> 1265 <li>Rewrote the API in XML generation script, includes a C parser and saves 1266 more informations needed for C# bindings</li> 1267</ul> 1268 1269<h3>2.4.28: Nov 22 2002</h3> 1270<ul> 1271 <li>a couple of python binding fixes</li> 1272 <li>2 bug fixes in the XML push parser</li> 1273 <li>potential memory leak removed (Martin Stoilov)</li> 1274 <li>fix to the configure script for Unix (Dimitri Papadopoulos)</li> 1275 <li>added encoding support for XInclude parse="text"</li> 1276 <li>autodetection of XHTML1 and specific serialization rules added</li> 1277 <li>nasty threading bug fixed (William Brack)</li> 1278</ul> 1279 1280<h3>2.4.27: Nov 17 2002</h3> 1281<ul> 1282 <li>fixes for the Python bindings</li> 1283 <li>a number of bug fixes: SGML catalogs, xmlParseBalancedChunkMemory(), 1284 HTML parser, Schemas (Charles Bozeman), document fragment support 1285 (Christian Glahn), xmlReconciliateNs (Brian Stafford), XPointer, 1286 xmlFreeNode(), xmlSAXParseMemory (Peter Jones), xmlGetNodePath (Petr 1287 Pajas), entities processing</li> 1288 <li>added grep to xmllint --shell</li> 1289 <li>VMS update patch from Craig A. Berry</li> 1290 <li>cleanup of the Windows build with support for more compilers (Igor), 1291 better thread support on Windows</li> 1292 <li>cleanup of Unix Makefiles and spec file</li> 1293 <li>Improvements to the documentation (John Fleck)</li> 1294</ul> 1295 1296<h3>2.4.26: Oct 18 2002</h3> 1297<ul> 1298 <li>Patches for Windows CE port, improvements on Windows paths handling</li> 1299 <li>Fixes to the validation code (DTD and Schemas), xmlNodeGetPath() , 1300 HTML serialization, Namespace compliance, and a number of small 1301 problems</li> 1302</ul> 1303 1304<h3>2.4.25: Sep 26 2002</h3> 1305<ul> 1306 <li>A number of bug fixes: XPath, validation, Python bindings, DOM and 1307 tree, xmlI/O, Html</li> 1308 <li>Serious rewrite of XInclude</li> 1309 <li>Made XML Schemas regexp part of the default build and APIs, small fix 1310 and improvement of the regexp core</li> 1311 <li>Changed the validation code to reuse XML Schemas regexp APIs</li> 1312 <li>Better handling of Windows file paths, improvement of Makefiles (Igor, 1313 Daniel Gehriger, Mark Vakoc)</li> 1314 <li>Improved the python I/O bindings, the tests, added resolver and regexp 1315 APIs</li> 1316 <li>New logos from Marc Liyanage</li> 1317 <li>Tutorial improvements: John Fleck, Christopher Harris</li> 1318 <li>Makefile: Fixes for AMD x86_64 (Mandrake), DESTDIR (Christophe 1319 Merlet)</li> 1320 <li>removal of all stderr/perror use for error reporting</li> 1321 <li>Better error reporting: XPath and DTD validation</li> 1322 <li>update of the trio portability layer (Bjorn Reese)</li> 1323</ul> 1324 1325<p><strong>2.4.24: Aug 22 2002</strong></p> 1326<ul> 1327 <li>XPath fixes (William), xf:escape-uri() (Wesley Terpstra)</li> 1328 <li>Python binding fixes: makefiles (William), generator, rpm build, x86-64 1329 (fcrozat)</li> 1330 <li>HTML <style> and boolean attributes serializer fixes</li> 1331 <li>C14N improvements by Aleksey</li> 1332 <li>doc cleanups: Rick Jones</li> 1333 <li>Windows compiler makefile updates: Igor and Elizabeth Barham</li> 1334 <li>XInclude: implementation of fallback and xml:base fixup added</li> 1335</ul> 1336 1337<h3>2.4.23: July 6 2002</h3> 1338<ul> 1339 <li>performances patches: Peter Jacobi</li> 1340 <li>c14n fixes, testsuite and performances: Aleksey Sanin</li> 1341 <li>added xmlDocFormatDump: Chema Celorio</li> 1342 <li>new tutorial: John Fleck</li> 1343 <li>new hash functions and performances: Sander Vesik, portability fix from 1344 Peter Jacobi</li> 1345 <li>a number of bug fixes: XPath (William Brack, Richard Jinks), XML and 1346 HTML parsers, ID lookup function</li> 1347 <li>removal of all remaining sprintf: Aleksey Sanin</li> 1348</ul> 1349 1350<h3>2.4.22: May 27 2002</h3> 1351<ul> 1352 <li>a number of bug fixes: configure scripts, base handling, parser, memory 1353 usage, HTML parser, XPath, documentation (Christian Cornelssen), 1354 indentation, URI parsing</li> 1355 <li>Optimizations for XMLSec, fixing and making public some of the network 1356 protocol handlers (Aleksey)</li> 1357 <li>performance patch from Gary Pennington</li> 1358 <li>Charles Bozeman provided date and time support for XML Schemas 1359 datatypes</li> 1360</ul> 1361 1362<h3>2.4.21: Apr 29 2002</h3> 1363 1364<p>This release is both a bug fix release and also contains the early XML 1365Schemas <a href="http://www.w3.org/TR/xmlschema-1/">structures</a> and <a 1366href="http://www.w3.org/TR/xmlschema-2/">datatypes</a> code, beware, all 1367interfaces are likely to change, there is huge holes, it is clearly a work in 1368progress and don't even think of putting this code in a production system, 1369it's actually not compiled in by default. The real fixes are:</p> 1370<ul> 1371 <li>a couple of bugs or limitations introduced in 2.4.20</li> 1372 <li>patches for Borland C++ and MSC by Igor</li> 1373 <li>some fixes on XPath strings and conformance patches by Richard 1374 Jinks</li> 1375 <li>patch from Aleksey for the ExcC14N specification</li> 1376 <li>OSF/1 bug fix by Bjorn</li> 1377</ul> 1378 1379<h3>2.4.20: Apr 15 2002</h3> 1380<ul> 1381 <li>bug fixes: file descriptor leak, XPath, HTML output, DTD validation</li> 1382 <li>XPath conformance testing by Richard Jinks</li> 1383 <li>Portability fixes: Solaris, MPE/iX, Windows, OSF/1, python bindings, 1384 libxml.m4</li> 1385</ul> 1386 1387<h3>2.4.19: Mar 25 2002</h3> 1388<ul> 1389 <li>bug fixes: half a dozen XPath bugs, Validation, ISO-Latin to UTF8 1390 encoder</li> 1391 <li>portability fixes in the HTTP code</li> 1392 <li>memory allocation checks using valgrind, and profiling tests</li> 1393 <li>revamp of the Windows build and Makefiles</li> 1394</ul> 1395 1396<h3>2.4.18: Mar 18 2002</h3> 1397<ul> 1398 <li>bug fixes: tree, SAX, canonicalization, validation, portability, 1399 XPath</li> 1400 <li>removed the --with-buffer option it was becoming unmaintainable</li> 1401 <li>serious cleanup of the Python makefiles</li> 1402 <li>speedup patch to XPath very effective for DocBook stylesheets</li> 1403 <li>Fixes for Windows build, cleanup of the documentation</li> 1404</ul> 1405 1406<h3>2.4.17: Mar 8 2002</h3> 1407<ul> 1408 <li>a lot of bug fixes, including "namespace nodes have no parents in 1409 XPath"</li> 1410 <li>fixed/improved the Python wrappers, added more examples and more 1411 regression tests, XPath extension functions can now return node-sets</li> 1412 <li>added the XML Canonicalization support from Aleksey Sanin</li> 1413</ul> 1414 1415<h3>2.4.16: Feb 20 2002</h3> 1416<ul> 1417 <li>a lot of bug fixes, most of them were triggered by the XML Testsuite 1418 from OASIS and W3C. Compliance has been significantly improved.</li> 1419 <li>a couple of portability fixes too.</li> 1420</ul> 1421 1422<h3>2.4.15: Feb 11 2002</h3> 1423<ul> 1424 <li>Fixed the Makefiles, especially the python module ones</li> 1425 <li>A few bug fixes and cleanup</li> 1426 <li>Includes cleanup</li> 1427</ul> 1428 1429<h3>2.4.14: Feb 8 2002</h3> 1430<ul> 1431 <li>Change of License to the <a 1432 href="http://www.opensource.org/licenses/mit-license.html">MIT 1433 License</a> basically for integration in XFree86 codebase, and removing 1434 confusion around the previous dual-licensing</li> 1435 <li>added Python bindings, beta software but should already be quite 1436 complete</li> 1437 <li>a large number of fixes and cleanups, especially for all tree 1438 manipulations</li> 1439 <li>cleanup of the headers, generation of a reference API definition in 1440 XML</li> 1441</ul> 1442 1443<h3>2.4.13: Jan 14 2002</h3> 1444<ul> 1445 <li>update of the documentation: John Fleck and Charlie Bozeman</li> 1446 <li>cleanup of timing code from Justin Fletcher</li> 1447 <li>fixes for Windows and initial thread support on Win32: Igor and Serguei 1448 Narojnyi</li> 1449 <li>Cygwin patch from Robert Collins</li> 1450 <li>added xmlSetEntityReferenceFunc() for Keith Isdale work on xsldbg</li> 1451</ul> 1452 1453<h3>2.4.12: Dec 7 2001</h3> 1454<ul> 1455 <li>a few bug fixes: thread (Gary Pennington), xmllint (Geert Kloosterman), 1456 XML parser (Robin Berjon), XPointer (Danny Jamshy), I/O cleanups 1457 (robert)</li> 1458 <li>Eric Lavigne contributed project files for MacOS</li> 1459 <li>some makefiles cleanups</li> 1460</ul> 1461 1462<h3>2.4.11: Nov 26 2001</h3> 1463<ul> 1464 <li>fixed a couple of errors in the includes, fixed a few bugs, some code 1465 cleanups</li> 1466 <li>xmllint man pages improvement by Heiko Rupp</li> 1467 <li>updated VMS build instructions from John A Fotheringham</li> 1468 <li>Windows Makefiles updates from Igor</li> 1469</ul> 1470 1471<h3>2.4.10: Nov 10 2001</h3> 1472<ul> 1473 <li>URI escaping fix (Joel Young)</li> 1474 <li>added xmlGetNodePath() (for paths or XPointers generation)</li> 1475 <li>Fixes namespace handling problems when using DTD and validation</li> 1476 <li>improvements on xmllint: Morus Walter patches for --format and 1477 --encode, Stefan Kost and Heiko Rupp improvements on the --shell</li> 1478 <li>fixes for xmlcatalog linking pointed by Weiqi Gao</li> 1479 <li>fixes to the HTML parser</li> 1480</ul> 1481 1482<h3>2.4.9: Nov 6 2001</h3> 1483<ul> 1484 <li>fixes more catalog bugs</li> 1485 <li>avoid a compilation problem, improve xmlGetLineNo()</li> 1486</ul> 1487 1488<h3>2.4.8: Nov 4 2001</h3> 1489<ul> 1490 <li>fixed SGML catalogs broken in previous release, updated xmlcatalog 1491 tool</li> 1492 <li>fixed a compile errors and some includes troubles.</li> 1493</ul> 1494 1495<h3>2.4.7: Oct 30 2001</h3> 1496<ul> 1497 <li>exported some debugging interfaces</li> 1498 <li>serious rewrite of the catalog code</li> 1499 <li>integrated Gary Pennington thread safety patch, added configure option 1500 and regression tests</li> 1501 <li>removed an HTML parser bug</li> 1502 <li>fixed a couple of potentially serious validation bugs</li> 1503 <li>integrated the SGML DocBook support in xmllint</li> 1504 <li>changed the nanoftp anonymous login passwd</li> 1505 <li>some I/O cleanup and a couple of interfaces for Perl wrapper</li> 1506 <li>general bug fixes</li> 1507 <li>updated xmllint man page by John Fleck</li> 1508 <li>some VMS and Windows updates</li> 1509</ul> 1510 1511<h3>2.4.6: Oct 10 2001</h3> 1512<ul> 1513 <li>added an updated man pages by John Fleck</li> 1514 <li>portability and configure fixes</li> 1515 <li>an infinite loop on the HTML parser was removed (William)</li> 1516 <li>Windows makefile patches from Igor</li> 1517 <li>fixed half a dozen bugs reported for libxml or libxslt</li> 1518 <li>updated xmlcatalog to be able to modify SGML super catalogs</li> 1519</ul> 1520 1521<h3>2.4.5: Sep 14 2001</h3> 1522<ul> 1523 <li>Remove a few annoying bugs in 2.4.4</li> 1524 <li>forces the HTML serializer to output decimal charrefs since some 1525 version of Netscape can't handle hexadecimal ones</li> 1526</ul> 1527 1528<h3>1.8.16: Sep 14 2001</h3> 1529<ul> 1530 <li>maintenance release of the old libxml1 branch, couple of bug and 1531 portability fixes</li> 1532</ul> 1533 1534<h3>2.4.4: Sep 12 2001</h3> 1535<ul> 1536 <li>added --convert to xmlcatalog, bug fixes and cleanups of XML 1537 Catalog</li> 1538 <li>a few bug fixes and some portability changes</li> 1539 <li>some documentation cleanups</li> 1540</ul> 1541 1542<h3>2.4.3: Aug 23 2001</h3> 1543<ul> 1544 <li>XML Catalog support see the doc</li> 1545 <li>New NaN/Infinity floating point code</li> 1546 <li>A few bug fixes</li> 1547</ul> 1548 1549<h3>2.4.2: Aug 15 2001</h3> 1550<ul> 1551 <li>adds xmlLineNumbersDefault() to control line number generation</li> 1552 <li>lot of bug fixes</li> 1553 <li>the Microsoft MSC projects files should now be up to date</li> 1554 <li>inheritance of namespaces from DTD defaulted attributes</li> 1555 <li>fixes a serious potential security bug</li> 1556 <li>added a --format option to xmllint</li> 1557</ul> 1558 1559<h3>2.4.1: July 24 2001</h3> 1560<ul> 1561 <li>possibility to keep line numbers in the tree</li> 1562 <li>some computation NaN fixes</li> 1563 <li>extension of the XPath API</li> 1564 <li>cleanup for alpha and ia64 targets</li> 1565 <li>patch to allow saving through HTTP PUT or POST</li> 1566</ul> 1567 1568<h3>2.4.0: July 10 2001</h3> 1569<ul> 1570 <li>Fixed a few bugs in XPath, validation, and tree handling.</li> 1571 <li>Fixed XML Base implementation, added a couple of examples to the 1572 regression tests</li> 1573 <li>A bit of cleanup</li> 1574</ul> 1575 1576<h3>2.3.14: July 5 2001</h3> 1577<ul> 1578 <li>fixed some entities problems and reduce memory requirement when 1579 substituting them</li> 1580 <li>lots of improvements in the XPath queries interpreter can be 1581 substantially faster</li> 1582 <li>Makefiles and configure cleanups</li> 1583 <li>Fixes to XPath variable eval, and compare on empty node set</li> 1584 <li>HTML tag closing bug fixed</li> 1585 <li>Fixed an URI reference computation problem when validating</li> 1586</ul> 1587 1588<h3>2.3.13: June 28 2001</h3> 1589<ul> 1590 <li>2.3.12 configure.in was broken as well as the push mode XML parser</li> 1591 <li>a few more fixes for compilation on Windows MSC by Yon Derek</li> 1592</ul> 1593 1594<h3>1.8.14: June 28 2001</h3> 1595<ul> 1596 <li>Zbigniew Chyla gave a patch to use the old XML parser in push mode</li> 1597 <li>Small Makefile fix</li> 1598</ul> 1599 1600<h3>2.3.12: June 26 2001</h3> 1601<ul> 1602 <li>lots of cleanup</li> 1603 <li>a couple of validation fix</li> 1604 <li>fixed line number counting</li> 1605 <li>fixed serious problems in the XInclude processing</li> 1606 <li>added support for UTF8 BOM at beginning of entities</li> 1607 <li>fixed a strange gcc optimizer bugs in xpath handling of float, gcc-3.0 1608 miscompile uri.c (William), Thomas Leitner provided a fix for the 1609 optimizer on Tru64</li> 1610 <li>incorporated Yon Derek and Igor Zlatkovic fixes and improvements for 1611 compilation on Windows MSC</li> 1612 <li>update of libxml-doc.el (Felix Natter)</li> 1613 <li>fixed 2 bugs in URI normalization code</li> 1614</ul> 1615 1616<h3>2.3.11: June 17 2001</h3> 1617<ul> 1618 <li>updates to trio, Makefiles and configure should fix some portability 1619 problems (alpha)</li> 1620 <li>fixed some HTML serialization problems (pre, script, and block/inline 1621 handling), added encoding aware APIs, cleanup of this code</li> 1622 <li>added xmlHasNsProp()</li> 1623 <li>implemented a specific PI for encoding support in the DocBook SGML 1624 parser</li> 1625 <li>some XPath fixes (-Infinity, / as a function parameter and namespaces 1626 node selection)</li> 1627 <li>fixed a performance problem and an error in the validation code</li> 1628 <li>fixed XInclude routine to implement the recursive behaviour</li> 1629 <li>fixed xmlFreeNode problem when libxml is included statically twice</li> 1630 <li>added --version to xmllint for bug reports</li> 1631</ul> 1632 1633<h3>2.3.10: June 1 2001</h3> 1634<ul> 1635 <li>fixed the SGML catalog support</li> 1636 <li>a number of reported bugs got fixed, in XPath, iconv detection, 1637 XInclude processing</li> 1638 <li>XPath string function should now handle unicode correctly</li> 1639</ul> 1640 1641<h3>2.3.9: May 19 2001</h3> 1642 1643<p>Lots of bugfixes, and added a basic SGML catalog support:</p> 1644<ul> 1645 <li>HTML push bugfix #54891 and another patch from Jonas Borgstr�m</li> 1646 <li>some serious speed optimization again</li> 1647 <li>some documentation cleanups</li> 1648 <li>trying to get better linking on Solaris (-R)</li> 1649 <li>XPath API cleanup from Thomas Broyer</li> 1650 <li>Validation bug fixed #54631, added a patch from Gary Pennington, fixed 1651 xmlValidGetValidElements()</li> 1652 <li>Added an INSTALL file</li> 1653 <li>Attribute removal added to API: #54433</li> 1654 <li>added a basic support for SGML catalogs</li> 1655 <li>fixed xmlKeepBlanksDefault(0) API</li> 1656 <li>bugfix in xmlNodeGetLang()</li> 1657 <li>fixed a small configure portability problem</li> 1658 <li>fixed an inversion of SYSTEM and PUBLIC identifier in HTML document</li> 1659</ul> 1660 1661<h3>1.8.13: May 14 2001</h3> 1662<ul> 1663 <li>bugfixes release of the old libxml1 branch used by Gnome</li> 1664</ul> 1665 1666<h3>2.3.8: May 3 2001</h3> 1667<ul> 1668 <li>Integrated an SGML DocBook parser for the Gnome project</li> 1669 <li>Fixed a few things in the HTML parser</li> 1670 <li>Fixed some XPath bugs raised by XSLT use, tried to fix the floating 1671 point portability issue</li> 1672 <li>Speed improvement (8M/s for SAX, 3M/s for DOM, 1.5M/s for 1673 DOM+validation using the XML REC as input and a 700MHz celeron).</li> 1674 <li>incorporated more Windows cleanup</li> 1675 <li>added xmlSaveFormatFile()</li> 1676 <li>fixed problems in copying nodes with entities references (gdome)</li> 1677 <li>removed some troubles surrounding the new validation module</li> 1678</ul> 1679 1680<h3>2.3.7: April 22 2001</h3> 1681<ul> 1682 <li>lots of small bug fixes, corrected XPointer</li> 1683 <li>Non deterministic content model validation support</li> 1684 <li>added xmlDocCopyNode for gdome2</li> 1685 <li>revamped the way the HTML parser handles end of tags</li> 1686 <li>XPath: corrections of namespaces support and number formatting</li> 1687 <li>Windows: Igor Zlatkovic patches for MSC compilation</li> 1688 <li>HTML output fixes from P C Chow and William M. Brack</li> 1689 <li>Improved validation speed sensible for DocBook</li> 1690 <li>fixed a big bug with ID declared in external parsed entities</li> 1691 <li>portability fixes, update of Trio from Bjorn Reese</li> 1692</ul> 1693 1694<h3>2.3.6: April 8 2001</h3> 1695<ul> 1696 <li>Code cleanup using extreme gcc compiler warning options, found and 1697 cleared half a dozen potential problem</li> 1698 <li>the Eazel team found an XML parser bug</li> 1699 <li>cleaned up the user of some of the string formatting function. used the 1700 trio library code to provide the one needed when the platform is missing 1701 them</li> 1702 <li>xpath: removed a memory leak and fixed the predicate evaluation 1703 problem, extended the testsuite and cleaned up the result. XPointer seems 1704 broken ...</li> 1705</ul> 1706 1707<h3>2.3.5: Mar 23 2001</h3> 1708<ul> 1709 <li>Biggest change is separate parsing and evaluation of XPath expressions, 1710 there is some new APIs for this too</li> 1711 <li>included a number of bug fixes(XML push parser, 51876, notations, 1712 52299)</li> 1713 <li>Fixed some portability issues</li> 1714</ul> 1715 1716<h3>2.3.4: Mar 10 2001</h3> 1717<ul> 1718 <li>Fixed bugs #51860 and #51861</li> 1719 <li>Added a global variable xmlDefaultBufferSize to allow default buffer 1720 size to be application tunable.</li> 1721 <li>Some cleanup in the validation code, still a bug left and this part 1722 should probably be rewritten to support ambiguous content model :-\</li> 1723 <li>Fix a couple of serious bugs introduced or raised by changes in 2.3.3 1724 parser</li> 1725 <li>Fixed another bug in xmlNodeGetContent()</li> 1726 <li>Bjorn fixed XPath node collection and Number formatting</li> 1727 <li>Fixed a loop reported in the HTML parsing</li> 1728 <li>blank space are reported even if the Dtd content model proves that they 1729 are formatting spaces, this is for XML conformance</li> 1730</ul> 1731 1732<h3>2.3.3: Mar 1 2001</h3> 1733<ul> 1734 <li>small change in XPath for XSLT</li> 1735 <li>documentation cleanups</li> 1736 <li>fix in validation by Gary Pennington</li> 1737 <li>serious parsing performances improvements</li> 1738</ul> 1739 1740<h3>2.3.2: Feb 24 2001</h3> 1741<ul> 1742 <li>chasing XPath bugs, found a bunch, completed some TODO</li> 1743 <li>fixed a Dtd parsing bug</li> 1744 <li>fixed a bug in xmlNodeGetContent</li> 1745 <li>ID/IDREF support partly rewritten by Gary Pennington</li> 1746</ul> 1747 1748<h3>2.3.1: Feb 15 2001</h3> 1749<ul> 1750 <li>some XPath and HTML bug fixes for XSLT</li> 1751 <li>small extension of the hash table interfaces for DOM gdome2 1752 implementation</li> 1753 <li>A few bug fixes</li> 1754</ul> 1755 1756<h3>2.3.0: Feb 8 2001 (2.2.12 was on 25 Jan but I didn't kept track)</h3> 1757<ul> 1758 <li>Lots of XPath bug fixes</li> 1759 <li>Add a mode with Dtd lookup but without validation error reporting for 1760 XSLT</li> 1761 <li>Add support for text node without escaping (XSLT)</li> 1762 <li>bug fixes for xmlCheckFilename</li> 1763 <li>validation code bug fixes from Gary Pennington</li> 1764 <li>Patch from Paul D. Smith correcting URI path normalization</li> 1765 <li>Patch to allow simultaneous install of libxml-devel and 1766 libxml2-devel</li> 1767 <li>the example Makefile is now fixed</li> 1768 <li>added HTML to the RPM packages</li> 1769 <li>tree copying bugfixes</li> 1770 <li>updates to Windows makefiles</li> 1771 <li>optimization patch from Bjorn Reese</li> 1772</ul> 1773 1774<h3>2.2.11: Jan 4 2001</h3> 1775<ul> 1776 <li>bunch of bug fixes (memory I/O, xpath, ftp/http, ...)</li> 1777 <li>added htmlHandleOmittedElem()</li> 1778 <li>Applied Bjorn Reese's IPV6 first patch</li> 1779 <li>Applied Paul D. Smith patches for validation of XInclude results</li> 1780 <li>added XPointer xmlns() new scheme support</li> 1781</ul> 1782 1783<h3>2.2.10: Nov 25 2000</h3> 1784<ul> 1785 <li>Fix the Windows problems of 2.2.8</li> 1786 <li>integrate OpenVMS patches</li> 1787 <li>better handling of some nasty HTML input</li> 1788 <li>Improved the XPointer implementation</li> 1789 <li>integrate a number of provided patches</li> 1790</ul> 1791 1792<h3>2.2.9: Nov 25 2000</h3> 1793<ul> 1794 <li>erroneous release :-(</li> 1795</ul> 1796 1797<h3>2.2.8: Nov 13 2000</h3> 1798<ul> 1799 <li>First version of <a href="http://www.w3.org/TR/xinclude">XInclude</a> 1800 support</li> 1801 <li>Patch in conditional section handling</li> 1802 <li>updated MS compiler project</li> 1803 <li>fixed some XPath problems</li> 1804 <li>added an URI escaping function</li> 1805 <li>some other bug fixes</li> 1806</ul> 1807 1808<h3>2.2.7: Oct 31 2000</h3> 1809<ul> 1810 <li>added message redirection</li> 1811 <li>XPath improvements (thanks TOM !)</li> 1812 <li>xmlIOParseDTD() added</li> 1813 <li>various small fixes in the HTML, URI, HTTP and XPointer support</li> 1814 <li>some cleanup of the Makefile, autoconf and the distribution content</li> 1815</ul> 1816 1817<h3>2.2.6: Oct 25 2000:</h3> 1818<ul> 1819 <li>Added an hash table module, migrated a number of internal structure to 1820 those</li> 1821 <li>Fixed a posteriori validation problems</li> 1822 <li>HTTP module cleanups</li> 1823 <li>HTML parser improvements (tag errors, script/style handling, attribute 1824 normalization)</li> 1825 <li>coalescing of adjacent text nodes</li> 1826 <li>couple of XPath bug fixes, exported the internal API</li> 1827</ul> 1828 1829<h3>2.2.5: Oct 15 2000:</h3> 1830<ul> 1831 <li>XPointer implementation and testsuite</li> 1832 <li>Lot of XPath fixes, added variable and functions registration, more 1833 tests</li> 1834 <li>Portability fixes, lots of enhancements toward an easy Windows build 1835 and release</li> 1836 <li>Late validation fixes</li> 1837 <li>Integrated a lot of contributed patches</li> 1838 <li>added memory management docs</li> 1839 <li>a performance problem when using large buffer seems fixed</li> 1840</ul> 1841 1842<h3>2.2.4: Oct 1 2000:</h3> 1843<ul> 1844 <li>main XPath problem fixed</li> 1845 <li>Integrated portability patches for Windows</li> 1846 <li>Serious bug fixes on the URI and HTML code</li> 1847</ul> 1848 1849<h3>2.2.3: Sep 17 2000</h3> 1850<ul> 1851 <li>bug fixes</li> 1852 <li>cleanup of entity handling code</li> 1853 <li>overall review of all loops in the parsers, all sprintf usage has been 1854 checked too</li> 1855 <li>Far better handling of larges Dtd. Validating against DocBook XML Dtd 1856 works smoothly now.</li> 1857</ul> 1858 1859<h3>1.8.10: Sep 6 2000</h3> 1860<ul> 1861 <li>bug fix release for some Gnome projects</li> 1862</ul> 1863 1864<h3>2.2.2: August 12 2000</h3> 1865<ul> 1866 <li>mostly bug fixes</li> 1867 <li>started adding routines to access xml parser context options</li> 1868</ul> 1869 1870<h3>2.2.1: July 21 2000</h3> 1871<ul> 1872 <li>a purely bug fixes release</li> 1873 <li>fixed an encoding support problem when parsing from a memory block</li> 1874 <li>fixed a DOCTYPE parsing problem</li> 1875 <li>removed a bug in the function allowing to override the memory 1876 allocation routines</li> 1877</ul> 1878 1879<h3>2.2.0: July 14 2000</h3> 1880<ul> 1881 <li>applied a lot of portability fixes</li> 1882 <li>better encoding support/cleanup and saving (content is now always 1883 encoded in UTF-8)</li> 1884 <li>the HTML parser now correctly handles encodings</li> 1885 <li>added xmlHasProp()</li> 1886 <li>fixed a serious problem with &#38;</li> 1887 <li>propagated the fix to FTP client</li> 1888 <li>cleanup, bugfixes, etc ...</li> 1889 <li>Added a page about <a href="encoding.html">libxml Internationalization 1890 support</a></li> 1891</ul> 1892 1893<h3>1.8.9: July 9 2000</h3> 1894<ul> 1895 <li>fixed the spec the RPMs should be better</li> 1896 <li>fixed a serious bug in the FTP implementation, released 1.8.9 to solve 1897 rpmfind users problem</li> 1898</ul> 1899 1900<h3>2.1.1: July 1 2000</h3> 1901<ul> 1902 <li>fixes a couple of bugs in the 2.1.0 packaging</li> 1903 <li>improvements on the HTML parser</li> 1904</ul> 1905 1906<h3>2.1.0 and 1.8.8: June 29 2000</h3> 1907<ul> 1908 <li>1.8.8 is mostly a commodity package for upgrading to libxml2 according 1909 to <a href="upgrade.html">new instructions</a>. It fixes a nasty problem 1910 about &#38; charref parsing</li> 1911 <li>2.1.0 also ease the upgrade from libxml v1 to the recent version. it 1912 also contains numerous fixes and enhancements: 1913 <ul> 1914 <li>added xmlStopParser() to stop parsing</li> 1915 <li>improved a lot parsing speed when there is large CDATA blocs</li> 1916 <li>includes XPath patches provided by Picdar Technology</li> 1917 <li>tried to fix as much as possible DTD validation and namespace 1918 related problems</li> 1919 <li>output to a given encoding has been added/tested</li> 1920 <li>lot of various fixes</li> 1921 </ul> 1922 </li> 1923</ul> 1924 1925<h3>2.0.0: Apr 12 2000</h3> 1926<ul> 1927 <li>First public release of libxml2. If you are using libxml, it's a good 1928 idea to check the 1.x to 2.x upgrade instructions. NOTE: while initially 1929 scheduled for Apr 3 the release occurred only on Apr 12 due to massive 1930 workload.</li> 1931 <li>The include are now located under $prefix/include/libxml (instead of 1932 $prefix/include/gnome-xml), they also are referenced by 1933 <pre>#include <libxml/xxx.h></pre> 1934 <p>instead of</p> 1935 <pre>#include "xxx.h"</pre> 1936 </li> 1937 <li>a new URI module for parsing URIs and following strictly RFC 2396</li> 1938 <li>the memory allocation routines used by libxml can now be overloaded 1939 dynamically by using xmlMemSetup()</li> 1940 <li>The previously CVS only tool tester has been renamed 1941 <strong>xmllint</strong> and is now installed as part of the libxml2 1942 package</li> 1943 <li>The I/O interface has been revamped. There is now ways to plug in 1944 specific I/O modules, either at the URI scheme detection level using 1945 xmlRegisterInputCallbacks() or by passing I/O functions when creating a 1946 parser context using xmlCreateIOParserCtxt()</li> 1947 <li>there is a C preprocessor macro LIBXML_VERSION providing the version 1948 number of the libxml module in use</li> 1949 <li>a number of optional features of libxml can now be excluded at 1950 configure time (FTP/HTTP/HTML/XPath/Debug)</li> 1951</ul> 1952 1953<h3>2.0.0beta: Mar 14 2000</h3> 1954<ul> 1955 <li>This is a first Beta release of libxml version 2</li> 1956 <li>It's available only from<a href="ftp://xmlsoft.org/">xmlsoft.org 1957 FTP</a>, it's packaged as libxml2-2.0.0beta and available as tar and 1958 RPMs</li> 1959 <li>This version is now the head in the Gnome CVS base, the old one is 1960 available under the tag LIB_XML_1_X</li> 1961 <li>This includes a very large set of changes. From a programmatic point 1962 of view applications should not have to be modified too much, check the 1963 <a href="upgrade.html">upgrade page</a></li> 1964 <li>Some interfaces may changes (especially a bit about encoding).</li> 1965 <li>the updates includes: 1966 <ul> 1967 <li>fix I18N support. ISO-Latin-x/UTF-8/UTF-16 (nearly) seems correctly 1968 handled now</li> 1969 <li>Better handling of entities, especially well-formedness checking 1970 and proper PEref extensions in external subsets</li> 1971 <li>DTD conditional sections</li> 1972 <li>Validation now correctly handle entities content</li> 1973 <li><a href="http://rpmfind.net/tools/gdome/messages/0039.html">change 1974 structures to accommodate DOM</a></li> 1975 </ul> 1976 </li> 1977 <li>Serious progress were made toward compliance, <a 1978 href="conf/result.html">here are the result of the test</a> against the 1979 OASIS testsuite (except the Japanese tests since I don't support that 1980 encoding yet). This URL is rebuilt every couple of hours using the CVS 1981 head version.</li> 1982</ul> 1983 1984<h3>1.8.7: Mar 6 2000</h3> 1985<ul> 1986 <li>This is a bug fix release:</li> 1987 <li>It is possible to disable the ignorable blanks heuristic used by 1988 libxml-1.x, a new function xmlKeepBlanksDefault(0) will allow this. Note 1989 that for adherence to XML spec, this behaviour will be disabled by 1990 default in 2.x . The same function will allow to keep compatibility for 1991 old code.</li> 1992 <li>Blanks in <a> </a> constructs are not ignored anymore, 1993 avoiding heuristic is really the Right Way :-\</li> 1994 <li>The unchecked use of snprintf which was breaking libxml-1.8.6 1995 compilation on some platforms has been fixed</li> 1996 <li>nanoftp.c nanohttp.c: Fixed '#' and '?' stripping when processing 1997 URIs</li> 1998</ul> 1999 2000<h3>1.8.6: Jan 31 2000</h3> 2001<ul> 2002 <li>added a nanoFTP transport module, debugged until the new version of <a 2003 href="http://rpmfind.net/linux/rpm2html/rpmfind.html">rpmfind</a> can use 2004 it without troubles</li> 2005</ul> 2006 2007<h3>1.8.5: Jan 21 2000</h3> 2008<ul> 2009 <li>adding APIs to parse a well balanced chunk of XML (production <a 2010 href="http://www.w3.org/TR/REC-xml#NT-content">[43] content</a> of the 2011 XML spec)</li> 2012 <li>fixed a hideous bug in xmlGetProp pointed by Rune.Djurhuus@fast.no</li> 2013 <li>Jody Goldberg <jgoldberg@home.com> provided another patch trying 2014 to solve the zlib checks problems</li> 2015 <li>The current state in gnome CVS base is expected to ship as 1.8.5 with 2016 gnumeric soon</li> 2017</ul> 2018 2019<h3>1.8.4: Jan 13 2000</h3> 2020<ul> 2021 <li>bug fixes, reintroduced xmlNewGlobalNs(), fixed xmlNewNs()</li> 2022 <li>all exit() call should have been removed from libxml</li> 2023 <li>fixed a problem with INCLUDE_WINSOCK on WIN32 platform</li> 2024 <li>added newDocFragment()</li> 2025</ul> 2026 2027<h3>1.8.3: Jan 5 2000</h3> 2028<ul> 2029 <li>a Push interface for the XML and HTML parsers</li> 2030 <li>a shell-like interface to the document tree (try tester --shell :-)</li> 2031 <li>lots of bug fixes and improvement added over XMas holidays</li> 2032 <li>fixed the DTD parsing code to work with the xhtml DTD</li> 2033 <li>added xmlRemoveProp(), xmlRemoveID() and xmlRemoveRef()</li> 2034 <li>Fixed bugs in xmlNewNs()</li> 2035 <li>External entity loading code has been revamped, now it uses 2036 xmlLoadExternalEntity(), some fix on entities processing were added</li> 2037 <li>cleaned up WIN32 includes of socket stuff</li> 2038</ul> 2039 2040<h3>1.8.2: Dec 21 1999</h3> 2041<ul> 2042 <li>I got another problem with includes and C++, I hope this issue is fixed 2043 for good this time</li> 2044 <li>Added a few tree modification functions: xmlReplaceNode, 2045 xmlAddPrevSibling, xmlAddNextSibling, xmlNodeSetName and 2046 xmlDocSetRootElement</li> 2047 <li>Tried to improve the HTML output with help from <a 2048 href="mailto:clahey@umich.edu">Chris Lahey</a></li> 2049</ul> 2050 2051<h3>1.8.1: Dec 18 1999</h3> 2052<ul> 2053 <li>various patches to avoid troubles when using libxml with C++ compilers 2054 the "namespace" keyword and C escaping in include files</li> 2055 <li>a problem in one of the core macros IS_CHAR was corrected</li> 2056 <li>fixed a bug introduced in 1.8.0 breaking default namespace processing, 2057 and more specifically the Dia application</li> 2058 <li>fixed a posteriori validation (validation after parsing, or by using a 2059 Dtd not specified in the original document)</li> 2060 <li>fixed a bug in</li> 2061</ul> 2062 2063<h3>1.8.0: Dec 12 1999</h3> 2064<ul> 2065 <li>cleanup, especially memory wise</li> 2066 <li>the parser should be more reliable, especially the HTML one, it should 2067 not crash, whatever the input !</li> 2068 <li>Integrated various patches, especially a speedup improvement for large 2069 dataset from <a href="mailto:cnygard@bellatlantic.net">Carl Nygard</a>, 2070 configure with --with-buffers to enable them.</li> 2071 <li>attribute normalization, oops should have been added long ago !</li> 2072 <li>attributes defaulted from DTDs should be available, xmlSetProp() now 2073 does entities escaping by default.</li> 2074</ul> 2075 2076<h3>1.7.4: Oct 25 1999</h3> 2077<ul> 2078 <li>Lots of HTML improvement</li> 2079 <li>Fixed some errors when saving both XML and HTML</li> 2080 <li>More examples, the regression tests should now look clean</li> 2081 <li>Fixed a bug with contiguous charref</li> 2082</ul> 2083 2084<h3>1.7.3: Sep 29 1999</h3> 2085<ul> 2086 <li>portability problems fixed</li> 2087 <li>snprintf was used unconditionally, leading to link problems on system 2088 were it's not available, fixed</li> 2089</ul> 2090 2091<h3>1.7.1: Sep 24 1999</h3> 2092<ul> 2093 <li>The basic type for strings manipulated by libxml has been renamed in 2094 1.7.1 from <strong>CHAR</strong> to <strong>xmlChar</strong>. The reason 2095 is that CHAR was conflicting with a predefined type on Windows. However 2096 on non WIN32 environment, compatibility is provided by the way of a 2097 <strong>#define </strong>.</li> 2098 <li>Changed another error : the use of a structure field called errno, and 2099 leading to troubles on platforms where it's a macro</li> 2100</ul> 2101 2102<h3>1.7.0: Sep 23 1999</h3> 2103<ul> 2104 <li>Added the ability to fetch remote DTD or parsed entities, see the <a 2105 href="html/libxml-nanohttp.html">nanohttp</a> module.</li> 2106 <li>Added an errno to report errors by another mean than a simple printf 2107 like callback</li> 2108 <li>Finished ID/IDREF support and checking when validation</li> 2109 <li>Serious memory leaks fixed (there is now a <a 2110 href="html/libxml-xmlmemory.html">memory wrapper</a> module)</li> 2111 <li>Improvement of <a href="http://www.w3.org/TR/xpath">XPath</a> 2112 implementation</li> 2113 <li>Added an HTML parser front-end</li> 2114</ul> 2115 2116<h2><a name="XML">XML</a></h2> 2117 2118<p><a href="http://www.w3.org/TR/REC-xml">XML is a standard</a> for 2119markup-based structured documents. Here is <a name="example">an example XML 2120document</a>:</p> 2121<pre><?xml version="1.0"?> 2122<EXAMPLE prop1="gnome is great" prop2="&amp; linux too"> 2123 <head> 2124 <title>Welcome to Gnome</title> 2125 </head> 2126 <chapter> 2127 <title>The Linux adventure</title> 2128 <p>bla bla bla ...</p> 2129 <image href="linus.gif"/> 2130 <p>...</p> 2131 </chapter> 2132</EXAMPLE></pre> 2133 2134<p>The first line specifies that it is an XML document and gives useful 2135information about its encoding. Then the rest of the document is a text 2136format whose structure is specified by tags between brackets. <strong>Each 2137tag opened has to be closed</strong>. XML is pedantic about this. However, if 2138a tag is empty (no content), a single tag can serve as both the opening and 2139closing tag if it ends with <code>/></code> rather than with 2140<code>></code>. Note that, for example, the image tag has no content (just 2141an attribute) and is closed by ending the tag with <code>/></code>.</p> 2142 2143<p>XML can be applied successfully to a wide range of tasks, ranging from 2144long term structured document maintenance (where it follows the steps of 2145SGML) to simple data encoding mechanisms like configuration file formatting 2146(glade), spreadsheets (gnumeric), or even shorter lived documents such as 2147WebDAV where it is used to encode remote calls between a client and a 2148server.</p> 2149 2150<h2><a name="XSLT">XSLT</a></h2> 2151 2152<p>Check <a href="http://xmlsoft.org/XSLT">the separate libxslt page</a></p> 2153 2154<p><a href="http://www.w3.org/TR/xslt">XSL Transformations</a>, is a 2155language for transforming XML documents into other XML documents (or 2156HTML/textual output).</p> 2157 2158<p>A separate library called libxslt is available implementing XSLT-1.0 for 2159libxml2. This module "libxslt" too can be found in the Gnome CVS base.</p> 2160 2161<p>You can check the <a 2162href="http://cvs.gnome.org/lxr/source/libxslt/FEATURES">features</a> 2163supported and the progresses on the <a 2164href="http://cvs.gnome.org/lxr/source/libxslt/ChangeLog" 2165name="Changelog">Changelog</a>.</p> 2166 2167<h2><a name="Python">Python and bindings</a></h2> 2168 2169<p>There are a number of language bindings and wrappers available for 2170libxml2, the list below is not exhaustive. Please contact the <a 2171href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a> 2172(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in 2173order to get updates to this list or to discuss the specific topic of libxml2 2174or libxslt wrappers or bindings:</p> 2175<ul> 2176 <li><a href="http://libxmlplusplus.sourceforge.net/">Libxml++</a> seems the 2177 most up-to-date C++ bindings for libxml2, check the <a 2178 href="http://libxmlplusplus.sourceforge.net/reference/html/hierarchy.html">documentation</a> 2179 and the <a 2180 href="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/libxmlplusplus/libxml%2b%2b/examples/">examples</a>.</li> 2181 <li>There is another <a href="http://libgdome-cpp.berlios.de/">C++ wrapper 2182 based on the gdome2 bindings</a> maintained by Tobias Peters.</li> 2183 <li>and a third C++ wrapper by Peter Jones <pjones@pmade.org> 2184 <p>Website: <a 2185 href="http://pmade.org/pjones/software/xmlwrapp/">http://pmade.org/pjones/software/xmlwrapp/</a></p> 2186 </li> 2187 <li><a 2188 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt 2189 Sergeant</a> developed <a 2190 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for 2191 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML 2192 application server</a>.</li> 2193 <li>If you're interested into scripting XML processing, have a look at <a 2194 href="http://xsh.sourceforge.net/">XSH</a> an XML editing shell based on 2195 Libxml2 Perl bindings.</li> 2196 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides an 2197 earlier version of the libxml/libxslt <a 2198 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a>.</li> 2199 <li>Gopal.V and Peter Minten develop <a 2200 href="http://savannah.gnu.org/projects/libxmlsharp">libxml#</a>, a set of 2201 C# libxml2 bindings.</li> 2202 <li>Petr Kozelka provides <a 2203 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue 2204 libxml2</a> with Kylix, Delphi and other Pascal compilers.</li> 2205 <li>Uwe Fechner also provides <a 2206 href="http://sourceforge.net/projects/idom2-pas/">idom2</a>, a DOM2 2207 implementation for Kylix2/D5/D6 from Borland.</li> 2208 <li>Wai-Sun "Squidster" Chia provides <a 2209 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and 2210 libxml2 bindings are also available in Ruby through the <a 2211 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module 2212 maintained by Tobias Peters.</li> 2213 <li>Steve Ball and contributors maintains <a 2214 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for 2215 Tcl</a>.</li> 2216 <li>There is support for libxml2 in the DOM module of PHP.</li> 2217 <li><a href="http://savannah.gnu.org/projects/classpathx/">LibxmlJ</a> is 2218 an effort to create a 100% JAXP-compatible Java wrapper for libxml2 and 2219 libxslt as part of GNU ClasspathX project.</li> 2220 <li>Patrick McPhee provides Rexx bindings fof libxml2 and libxslt, look for 2221 <a href="http://www.interlog.com/~ptjm/software.html">RexxXML</a>.</li> 2222</ul> 2223 2224<p>The distribution includes a set of Python bindings, which are guaranteed 2225to be maintained as part of the library in the future, though the Python 2226interface have not yet reached the completeness of the C API.</p> 2227 2228<p><a href="mailto:stephane.bidoul@softwareag.com">St�phane Bidoul</a> 2229maintains <a href="http://users.skynet.be/sbi/libxml-python/">a Windows port 2230of the Python bindings</a>.</p> 2231 2232<p>Note to people interested in building bindings, the API is formalized as 2233<a href="libxml2-api.xml">an XML API description file</a> which allows to 2234automate a large part of the Python bindings, this includes function 2235descriptions, enums, structures, typedefs, etc... The Python script used to 2236build the bindings is python/generator.py in the source distribution.</p> 2237 2238<p>To install the Python bindings there are 2 options:</p> 2239<ul> 2240 <li>If you use an RPM based distribution, simply install the <a 2241 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python 2242 RPM</a> (and if needed the <a 2243 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python 2244 RPM</a>).</li> 2245 <li>Otherwise use the <a href="ftp://xmlsoft.org/python/">libxml2-python 2246 module distribution</a> corresponding to your installed version of 2247 libxml2 and libxslt. Note that to install it you will need both libxml2 2248 and libxslt installed and run "python setup.py build install" in the 2249 module tree.</li> 2250</ul> 2251 2252<p>The distribution includes a set of examples and regression tests for the 2253python bindings in the <code>python/tests</code> directory. Here are some 2254excerpts from those tests:</p> 2255 2256<h3>tst.py:</h3> 2257 2258<p>This is a basic test of the file interface and DOM navigation:</p> 2259<pre>import libxml2, sys 2260 2261doc = libxml2.parseFile("tst.xml") 2262if doc.name != "tst.xml": 2263 print "doc.name failed" 2264 sys.exit(1) 2265root = doc.children 2266if root.name != "doc": 2267 print "root.name failed" 2268 sys.exit(1) 2269child = root.children 2270if child.name != "foo": 2271 print "child.name failed" 2272 sys.exit(1) 2273doc.freeDoc()</pre> 2274 2275<p>The Python module is called libxml2; parseFile is the equivalent of 2276xmlParseFile (most of the bindings are automatically generated, and the xml 2277prefix is removed and the casing convention are kept). All node seen at the 2278binding level share the same subset of accessors:</p> 2279<ul> 2280 <li><code>name</code> : returns the node name</li> 2281 <li><code>type</code> : returns a string indicating the node type</li> 2282 <li><code>content</code> : returns the content of the node, it is based on 2283 xmlNodeGetContent() and hence is recursive.</li> 2284 <li><code>parent</code> , <code>children</code>, <code>last</code>, 2285 <code>next</code>, <code>prev</code>, <code>doc</code>, 2286 <code>properties</code>: pointing to the associated element in the tree, 2287 those may return None in case no such link exists.</li> 2288</ul> 2289 2290<p>Also note the need to explicitly deallocate documents with freeDoc() . 2291Reference counting for libxml2 trees would need quite a lot of work to 2292function properly, and rather than risk memory leaks if not implemented 2293correctly it sounds safer to have an explicit function to free a tree. The 2294wrapper python objects like doc, root or child are them automatically garbage 2295collected.</p> 2296 2297<h3>validate.py:</h3> 2298 2299<p>This test check the validation interfaces and redirection of error 2300messages:</p> 2301<pre>import libxml2 2302 2303#deactivate error messages from the validation 2304def noerr(ctx, str): 2305 pass 2306 2307libxml2.registerErrorHandler(noerr, None) 2308 2309ctxt = libxml2.createFileParserCtxt("invalid.xml") 2310ctxt.validate(1) 2311ctxt.parseDocument() 2312doc = ctxt.doc() 2313valid = ctxt.isValid() 2314doc.freeDoc() 2315if valid != 0: 2316 print "validity check failed"</pre> 2317 2318<p>The first thing to notice is the call to registerErrorHandler(), it 2319defines a new error handler global to the library. It is used to avoid seeing 2320the error messages when trying to validate the invalid document.</p> 2321 2322<p>The main interest of that test is the creation of a parser context with 2323createFileParserCtxt() and how the behaviour can be changed before calling 2324parseDocument() . Similarly the informations resulting from the parsing phase 2325are also available using context methods.</p> 2326 2327<p>Contexts like nodes are defined as class and the libxml2 wrappers maps the 2328C function interfaces in terms of objects method as much as possible. The 2329best to get a complete view of what methods are supported is to look at the 2330libxml2.py module containing all the wrappers.</p> 2331 2332<h3>push.py:</h3> 2333 2334<p>This test show how to activate the push parser interface:</p> 2335<pre>import libxml2 2336 2337ctxt = libxml2.createPushParser(None, "<foo", 4, "test.xml") 2338ctxt.parseChunk("/>", 2, 1) 2339doc = ctxt.doc() 2340 2341doc.freeDoc()</pre> 2342 2343<p>The context is created with a special call based on the 2344xmlCreatePushParser() from the C library. The first argument is an optional 2345SAX callback object, then the initial set of data, the length and the name of 2346the resource in case URI-References need to be computed by the parser.</p> 2347 2348<p>Then the data are pushed using the parseChunk() method, the last call 2349setting the third argument terminate to 1.</p> 2350 2351<h3>pushSAX.py:</h3> 2352 2353<p>this test show the use of the event based parsing interfaces. In this case 2354the parser does not build a document, but provides callback information as 2355the parser makes progresses analyzing the data being provided:</p> 2356<pre>import libxml2 2357log = "" 2358 2359class callback: 2360 def startDocument(self): 2361 global log 2362 log = log + "startDocument:" 2363 2364 def endDocument(self): 2365 global log 2366 log = log + "endDocument:" 2367 2368 def startElement(self, tag, attrs): 2369 global log 2370 log = log + "startElement %s %s:" % (tag, attrs) 2371 2372 def endElement(self, tag): 2373 global log 2374 log = log + "endElement %s:" % (tag) 2375 2376 def characters(self, data): 2377 global log 2378 log = log + "characters: %s:" % (data) 2379 2380 def warning(self, msg): 2381 global log 2382 log = log + "warning: %s:" % (msg) 2383 2384 def error(self, msg): 2385 global log 2386 log = log + "error: %s:" % (msg) 2387 2388 def fatalError(self, msg): 2389 global log 2390 log = log + "fatalError: %s:" % (msg) 2391 2392handler = callback() 2393 2394ctxt = libxml2.createPushParser(handler, "<foo", 4, "test.xml") 2395chunk = " url='tst'>b" 2396ctxt.parseChunk(chunk, len(chunk), 0) 2397chunk = "ar</foo>" 2398ctxt.parseChunk(chunk, len(chunk), 1) 2399 2400reference = "startDocument:startElement foo {'url': 'tst'}:" + \ 2401 "characters: bar:endElement foo:endDocument:" 2402if log != reference: 2403 print "Error got: %s" % log 2404 print "Expected: %s" % reference</pre> 2405 2406<p>The key object in that test is the handler, it provides a number of entry 2407points which can be called by the parser as it makes progresses to indicate 2408the information set obtained. The full set of callback is larger than what 2409the callback class in that specific example implements (see the SAX 2410definition for a complete list). The wrapper will only call those supplied by 2411the object when activated. The startElement receives the names of the element 2412and a dictionary containing the attributes carried by this element.</p> 2413 2414<p>Also note that the reference string generated from the callback shows a 2415single character call even though the string "bar" is passed to the parser 2416from 2 different call to parseChunk()</p> 2417 2418<h3>xpath.py:</h3> 2419 2420<p>This is a basic test of XPath wrappers support</p> 2421<pre>import libxml2 2422 2423doc = libxml2.parseFile("tst.xml") 2424ctxt = doc.xpathNewContext() 2425res = ctxt.xpathEval("//*") 2426if len(res) != 2: 2427 print "xpath query: wrong node set size" 2428 sys.exit(1) 2429if res[0].name != "doc" or res[1].name != "foo": 2430 print "xpath query: wrong node set value" 2431 sys.exit(1) 2432doc.freeDoc() 2433ctxt.xpathFreeContext()</pre> 2434 2435<p>This test parses a file, then create an XPath context to evaluate XPath 2436expression on it. The xpathEval() method execute an XPath query and returns 2437the result mapped in a Python way. String and numbers are natively converted, 2438and node sets are returned as a tuple of libxml2 Python nodes wrappers. Like 2439the document, the XPath context need to be freed explicitly, also not that 2440the result of the XPath query may point back to the document tree and hence 2441the document must be freed after the result of the query is used.</p> 2442 2443<h3>xpathext.py:</h3> 2444 2445<p>This test shows how to extend the XPath engine with functions written in 2446python:</p> 2447<pre>import libxml2 2448 2449def foo(ctx, x): 2450 return x + 1 2451 2452doc = libxml2.parseFile("tst.xml") 2453ctxt = doc.xpathNewContext() 2454libxml2.registerXPathFunction(ctxt._o, "foo", None, foo) 2455res = ctxt.xpathEval("foo(1)") 2456if res != 2: 2457 print "xpath extension failure" 2458doc.freeDoc() 2459ctxt.xpathFreeContext()</pre> 2460 2461<p>Note how the extension function is registered with the context (but that 2462part is not yet finalized, this may change slightly in the future).</p> 2463 2464<h3>tstxpath.py:</h3> 2465 2466<p>This test is similar to the previous one but shows how the extension 2467function can access the XPath evaluation context:</p> 2468<pre>def foo(ctx, x): 2469 global called 2470 2471 # 2472 # test that access to the XPath evaluation contexts 2473 # 2474 pctxt = libxml2.xpathParserContext(_obj=ctx) 2475 ctxt = pctxt.context() 2476 called = ctxt.function() 2477 return x + 1</pre> 2478 2479<p>All the interfaces around the XPath parser(or rather evaluation) context 2480are not finalized, but it should be sufficient to do contextual work at the 2481evaluation point.</p> 2482 2483<h3>Memory debugging:</h3> 2484 2485<p>last but not least, all tests starts with the following prologue:</p> 2486<pre>#memory debug specific 2487libxml2.debugMemory(1)</pre> 2488 2489<p>and ends with the following epilogue:</p> 2490<pre>#memory debug specific 2491libxml2.cleanupParser() 2492if libxml2.debugMemory(1) == 0: 2493 print "OK" 2494else: 2495 print "Memory leak %d bytes" % (libxml2.debugMemory(1)) 2496 libxml2.dumpMemory()</pre> 2497 2498<p>Those activate the memory debugging interface of libxml2 where all 2499allocated block in the library are tracked. The prologue then cleans up the 2500library state and checks that all allocated memory has been freed. If not it 2501calls dumpMemory() which saves that list in a <code>.memdump</code> file.</p> 2502 2503<h2><a name="architecture">libxml2 architecture</a></h2> 2504 2505<p>Libxml2 is made of multiple components; some of them are optional, and 2506most of the block interfaces are public. The main components are:</p> 2507<ul> 2508 <li>an Input/Output layer</li> 2509 <li>FTP and HTTP client layers (optional)</li> 2510 <li>an Internationalization layer managing the encodings support</li> 2511 <li>a URI module</li> 2512 <li>the XML parser and its basic SAX interface</li> 2513 <li>an HTML parser using the same SAX interface (optional)</li> 2514 <li>a SAX tree module to build an in-memory DOM representation</li> 2515 <li>a tree module to manipulate the DOM representation</li> 2516 <li>a validation module using the DOM representation (optional)</li> 2517 <li>an XPath module for global lookup in a DOM representation 2518 (optional)</li> 2519 <li>a debug module (optional)</li> 2520</ul> 2521 2522<p>Graphically this gives the following:</p> 2523 2524<p><img src="libxml.gif" alt="a graphical view of the various"></p> 2525 2526<p></p> 2527 2528<h2><a name="tree">The tree output</a></h2> 2529 2530<p>The parser returns a tree built during the document analysis. The value 2531returned is an <strong>xmlDocPtr</strong> (i.e., a pointer to an 2532<strong>xmlDoc</strong> structure). This structure contains information such 2533as the file name, the document type, and a <strong>children</strong> pointer 2534which is the root of the document (or more exactly the first child under the 2535root which is the document). The tree is made of <strong>xmlNode</strong>s, 2536chained in double-linked lists of siblings and with a children<->parent 2537relationship. An xmlNode can also carry properties (a chain of xmlAttr 2538structures). An attribute may have a value which is a list of TEXT or 2539ENTITY_REF nodes.</p> 2540 2541<p>Here is an example (erroneous with respect to the XML spec since there 2542should be only one ELEMENT under the root):</p> 2543 2544<p><img src="structure.gif" alt=" structure.gif "></p> 2545 2546<p>In the source package there is a small program (not installed by default) 2547called <strong>xmllint</strong> which parses XML files given as argument and 2548prints them back as parsed. This is useful for detecting errors both in XML 2549code and in the XML parser itself. It has an option <strong>--debug</strong> 2550which prints the actual in-memory structure of the document; here is the 2551result with the <a href="#example">example</a> given before:</p> 2552<pre>DOCUMENT 2553version=1.0 2554standalone=true 2555 ELEMENT EXAMPLE 2556 ATTRIBUTE prop1 2557 TEXT 2558 content=gnome is great 2559 ATTRIBUTE prop2 2560 ENTITY_REF 2561 TEXT 2562 content= linux too 2563 ELEMENT head 2564 ELEMENT title 2565 TEXT 2566 content=Welcome to Gnome 2567 ELEMENT chapter 2568 ELEMENT title 2569 TEXT 2570 content=The Linux adventure 2571 ELEMENT p 2572 TEXT 2573 content=bla bla bla ... 2574 ELEMENT image 2575 ATTRIBUTE href 2576 TEXT 2577 content=linus.gif 2578 ELEMENT p 2579 TEXT 2580 content=...</pre> 2581 2582<p>This should be useful for learning the internal representation model.</p> 2583 2584<h2><a name="interface">The SAX interface</a></h2> 2585 2586<p>Sometimes the DOM tree output is just too large to fit reasonably into 2587memory. In that case (and if you don't expect to save back the XML document 2588loaded using libxml), it's better to use the SAX interface of libxml. SAX is 2589a <strong>callback-based interface</strong> to the parser. Before parsing, 2590the application layer registers a customized set of callbacks which are 2591called by the library as it progresses through the XML input.</p> 2592 2593<p>To get more detailed step-by-step guidance on using the SAX interface of 2594libxml, see the <a 2595href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">nice 2596documentation</a>.written by <a href="mailto:james@daa.com.au">James 2597Henstridge</a>.</p> 2598 2599<p>You can debug the SAX behaviour by using the <strong>testSAX</strong> 2600program located in the gnome-xml module (it's usually not shipped in the 2601binary packages of libxml, but you can find it in the tar source 2602distribution). Here is the sequence of callbacks that would be reported by 2603testSAX when parsing the example XML document shown earlier:</p> 2604<pre>SAX.setDocumentLocator() 2605SAX.startDocument() 2606SAX.getEntity(amp) 2607SAX.startElement(EXAMPLE, prop1='gnome is great', prop2='&amp; linux too') 2608SAX.characters( , 3) 2609SAX.startElement(head) 2610SAX.characters( , 4) 2611SAX.startElement(title) 2612SAX.characters(Welcome to Gnome, 16) 2613SAX.endElement(title) 2614SAX.characters( , 3) 2615SAX.endElement(head) 2616SAX.characters( , 3) 2617SAX.startElement(chapter) 2618SAX.characters( , 4) 2619SAX.startElement(title) 2620SAX.characters(The Linux adventure, 19) 2621SAX.endElement(title) 2622SAX.characters( , 4) 2623SAX.startElement(p) 2624SAX.characters(bla bla bla ..., 15) 2625SAX.endElement(p) 2626SAX.characters( , 4) 2627SAX.startElement(image, href='linus.gif') 2628SAX.endElement(image) 2629SAX.characters( , 4) 2630SAX.startElement(p) 2631SAX.characters(..., 3) 2632SAX.endElement(p) 2633SAX.characters( , 3) 2634SAX.endElement(chapter) 2635SAX.characters( , 1) 2636SAX.endElement(EXAMPLE) 2637SAX.endDocument()</pre> 2638 2639<p>Most of the other interfaces of libxml2 are based on the DOM tree-building 2640facility, so nearly everything up to the end of this document presupposes the 2641use of the standard DOM tree build. Note that the DOM tree itself is built by 2642a set of registered default callbacks, without internal specific 2643interface.</p> 2644 2645<h2><a name="Validation">Validation & DTDs</a></h2> 2646 2647<p>Table of Content:</p> 2648<ol> 2649 <li><a href="#General5">General overview</a></li> 2650 <li><a href="#definition">The definition</a></li> 2651 <li><a href="#Simple">Simple rules</a> 2652 <ol> 2653 <li><a href="#reference">How to reference a DTD from a document</a></li> 2654 <li><a href="#Declaring">Declaring elements</a></li> 2655 <li><a href="#Declaring1">Declaring attributes</a></li> 2656 </ol> 2657 </li> 2658 <li><a href="#Some">Some examples</a></li> 2659 <li><a href="#validate">How to validate</a></li> 2660 <li><a href="#Other">Other resources</a></li> 2661</ol> 2662 2663<h3><a name="General5">General overview</a></h3> 2664 2665<p>Well what is validation and what is a DTD ?</p> 2666 2667<p>DTD is the acronym for Document Type Definition. This is a description of 2668the content for a family of XML files. This is part of the XML 1.0 2669specification, and allows one to describe and verify that a given document 2670instance conforms to the set of rules detailing its structure and content.</p> 2671 2672<p>Validation is the process of checking a document against a DTD (more 2673generally against a set of construction rules).</p> 2674 2675<p>The validation process and building DTDs are the two most difficult parts 2676of the XML life cycle. Briefly a DTD defines all the possible elements to be 2677found within your document, what is the formal shape of your document tree 2678(by defining the allowed content of an element; either text, a regular 2679expression for the allowed list of children, or mixed content i.e. both text 2680and children). The DTD also defines the valid attributes for all elements and 2681the types of those attributes.</p> 2682 2683<h3><a name="definition1">The definition</a></h3> 2684 2685<p>The <a href="http://www.w3.org/TR/REC-xml">W3C XML Recommendation</a> (<a 2686href="http://www.xml.com/axml/axml.html">Tim Bray's annotated version of 2687Rev1</a>):</p> 2688<ul> 2689 <li><a href="http://www.w3.org/TR/REC-xml#elemdecls">Declaring 2690 elements</a></li> 2691 <li><a href="http://www.w3.org/TR/REC-xml#attdecls">Declaring 2692 attributes</a></li> 2693</ul> 2694 2695<p>(unfortunately) all this is inherited from the SGML world, the syntax is 2696ancient...</p> 2697 2698<h3><a name="Simple1">Simple rules</a></h3> 2699 2700<p>Writing DTDs can be done in many ways. The rules to build them if you need 2701something permanent or something which can evolve over time can be radically 2702different. Really complex DTDs like DocBook ones are flexible but quite 2703harder to design. I will just focus on DTDs for a formats with a fixed simple 2704structure. It is just a set of basic rules, and definitely not exhaustive nor 2705usable for complex DTD design.</p> 2706 2707<h4><a name="reference1">How to reference a DTD from a document</a>:</h4> 2708 2709<p>Assuming the top element of the document is <code>spec</code> and the dtd 2710is placed in the file <code>mydtd</code> in the subdirectory 2711<code>dtds</code> of the directory from where the document were loaded:</p> 2712 2713<p><code><!DOCTYPE spec SYSTEM "dtds/mydtd"></code></p> 2714 2715<p>Notes:</p> 2716<ul> 2717 <li>The system string is actually an URI-Reference (as defined in <a 2718 href="http://www.ietf.org/rfc/rfc2396.txt">RFC 2396</a>) so you can use a 2719 full URL string indicating the location of your DTD on the Web. This is a 2720 really good thing to do if you want others to validate your document.</li> 2721 <li>It is also possible to associate a <code>PUBLIC</code> identifier (a 2722 magic string) so that the DTD is looked up in catalogs on the client side 2723 without having to locate it on the web.</li> 2724 <li>A DTD contains a set of element and attribute declarations, but they 2725 don't define what the root of the document should be. This is explicitly 2726 told to the parser/validator as the first element of the 2727 <code>DOCTYPE</code> declaration.</li> 2728</ul> 2729 2730<h4><a name="Declaring2">Declaring elements</a>:</h4> 2731 2732<p>The following declares an element <code>spec</code>:</p> 2733 2734<p><code><!ELEMENT spec (front, body, back?)></code></p> 2735 2736<p>It also expresses that the spec element contains one <code>front</code>, 2737one <code>body</code> and one optional <code>back</code> children elements in 2738this order. The declaration of one element of the structure and its content 2739are done in a single declaration. Similarly the following declares 2740<code>div1</code> elements:</p> 2741 2742<p><code><!ELEMENT div1 (head, (p | list | note)*, div2?)></code></p> 2743 2744<p>which means div1 contains one <code>head</code> then a series of optional 2745<code>p</code>, <code>list</code>s and <code>note</code>s and then an 2746optional <code>div2</code>. And last but not least an element can contain 2747text:</p> 2748 2749<p><code><!ELEMENT b (#PCDATA)></code></p> 2750 2751<p><code>b</code> contains text or being of mixed content (text and elements 2752in no particular order):</p> 2753 2754<p><code><!ELEMENT p (#PCDATA|a|ul|b|i|em)*></code></p> 2755 2756<p><code>p </code>can contain text or <code>a</code>, <code>ul</code>, 2757<code>b</code>, <code>i </code>or <code>em</code> elements in no particular 2758order.</p> 2759 2760<h4><a name="Declaring1">Declaring attributes</a>:</h4> 2761 2762<p>Again the attributes declaration includes their content definition:</p> 2763 2764<p><code><!ATTLIST termdef name CDATA #IMPLIED></code></p> 2765 2766<p>means that the element <code>termdef</code> can have a <code>name</code> 2767attribute containing text (<code>CDATA</code>) and which is optional 2768(<code>#IMPLIED</code>). The attribute value can also be defined within a 2769set:</p> 2770 2771<p><code><!ATTLIST list type (bullets|ordered|glossary) 2772"ordered"></code></p> 2773 2774<p>means <code>list</code> element have a <code>type</code> attribute with 3 2775allowed values "bullets", "ordered" or "glossary" and which default to 2776"ordered" if the attribute is not explicitly specified.</p> 2777 2778<p>The content type of an attribute can be text (<code>CDATA</code>), 2779anchor/reference/references 2780(<code>ID</code>/<code>IDREF</code>/<code>IDREFS</code>), entity(ies) 2781(<code>ENTITY</code>/<code>ENTITIES</code>) or name(s) 2782(<code>NMTOKEN</code>/<code>NMTOKENS</code>). The following defines that a 2783<code>chapter</code> element can have an optional <code>id</code> attribute 2784of type <code>ID</code>, usable for reference from attribute of type 2785IDREF:</p> 2786 2787<p><code><!ATTLIST chapter id ID #IMPLIED></code></p> 2788 2789<p>The last value of an attribute definition can be <code>#REQUIRED 2790</code>meaning that the attribute has to be given, <code>#IMPLIED</code> 2791meaning that it is optional, or the default value (possibly prefixed by 2792<code>#FIXED</code> if it is the only allowed).</p> 2793 2794<p>Notes:</p> 2795<ul> 2796 <li>Usually the attributes pertaining to a given element are declared in a 2797 single expression, but it is just a convention adopted by a lot of DTD 2798 writers: 2799 <pre><!ATTLIST termdef 2800 id ID #REQUIRED 2801 name CDATA #IMPLIED></pre> 2802 <p>The previous construct defines both <code>id</code> and 2803 <code>name</code> attributes for the element <code>termdef</code>.</p> 2804 </li> 2805</ul> 2806 2807<h3><a name="Some1">Some examples</a></h3> 2808 2809<p>The directory <code>test/valid/dtds/</code> in the libxml2 distribution 2810contains some complex DTD examples. The example in the file 2811<code>test/valid/dia.xml</code> shows an XML file where the simple DTD is 2812directly included within the document.</p> 2813 2814<h3><a name="validate1">How to validate</a></h3> 2815 2816<p>The simplest way is to use the xmllint program included with libxml. The 2817<code>--valid</code> option turns-on validation of the files given as input. 2818For example the following validates a copy of the first revision of the XML 28191.0 specification:</p> 2820 2821<p><code>xmllint --valid --noout test/valid/REC-xml-19980210.xml</code></p> 2822 2823<p>the -- noout is used to disable output of the resulting tree.</p> 2824 2825<p>The <code>--dtdvalid dtd</code> allows validation of the document(s) 2826against a given DTD.</p> 2827 2828<p>Libxml2 exports an API to handle DTDs and validation, check the <a 2829href="http://xmlsoft.org/html/libxml-valid.html">associated 2830description</a>.</p> 2831 2832<h3><a name="Other1">Other resources</a></h3> 2833 2834<p>DTDs are as old as SGML. So there may be a number of examples on-line, I 2835will just list one for now, others pointers welcome:</p> 2836<ul> 2837 <li><a href="http://www.xml101.com:8081/dtd/">XML-101 DTD</a></li> 2838</ul> 2839 2840<p>I suggest looking at the examples found under test/valid/dtd and any of 2841the large number of books available on XML. The dia example in test/valid 2842should be both simple and complete enough to allow you to build your own.</p> 2843 2844<p></p> 2845 2846<h2><a name="Memory">Memory Management</a></h2> 2847 2848<p>Table of Content:</p> 2849<ol> 2850 <li><a href="#General3">General overview</a></li> 2851 <li><a href="#setting">Setting libxml2 set of memory routines</a></li> 2852 <li><a href="#cleanup">Cleaning up after parsing</a></li> 2853 <li><a href="#Debugging">Debugging routines</a></li> 2854 <li><a href="#General4">General memory requirements</a></li> 2855</ol> 2856 2857<h3><a name="General3">General overview</a></h3> 2858 2859<p>The module <code><a 2860href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlmemory.h</a></code> 2861provides the interfaces to the libxml2 memory system:</p> 2862<ul> 2863 <li>libxml2 does not use the libc memory allocator directly but xmlFree(), 2864 xmlMalloc() and xmlRealloc()</li> 2865 <li>those routines can be reallocated to a specific set of routine, by 2866 default the libc ones i.e. free(), malloc() and realloc()</li> 2867 <li>the xmlmemory.c module includes a set of debugging routine</li> 2868</ul> 2869 2870<h3><a name="setting">Setting libxml2 set of memory routines</a></h3> 2871 2872<p>It is sometimes useful to not use the default memory allocator, either for 2873debugging, analysis or to implement a specific behaviour on memory management 2874(like on embedded systems). Two function calls are available to do so:</p> 2875<ul> 2876 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemGet 2877 ()</a> which return the current set of functions in use by the parser</li> 2878 <li><a 2879 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemSetup()</a> 2880 which allow to set up a new set of memory allocation functions</li> 2881</ul> 2882 2883<p>Of course a call to xmlMemSetup() should probably be done before calling 2884any other libxml2 routines (unless you are sure your allocations routines are 2885compatibles).</p> 2886 2887<h3><a name="cleanup">Cleaning up after parsing</a></h3> 2888 2889<p>Libxml2 is not stateless, there is a few set of memory structures needing 2890allocation before the parser is fully functional (some encoding structures 2891for example). This also mean that once parsing is finished there is a tiny 2892amount of memory (a few hundred bytes) which can be recollected if you don't 2893reuse the parser immediately:</p> 2894<ul> 2895 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlCleanupParser 2896 ()</a> is a centralized routine to free the parsing states. Note that it 2897 won't deallocate any produced tree if any (use the xmlFreeDoc() and 2898 related routines for this).</li> 2899 <li><a href="http://xmlsoft.org/html/libxml-parser.html">xmlInitParser 2900 ()</a> is the dual routine allowing to preallocate the parsing state 2901 which can be useful for example to avoid initialization reentrancy 2902 problems when using libxml2 in multithreaded applications</li> 2903</ul> 2904 2905<p>Generally xmlCleanupParser() is safe, if needed the state will be rebuild 2906at the next invocation of parser routines, but be careful of the consequences 2907in multithreaded applications.</p> 2908 2909<h3><a name="Debugging">Debugging routines</a></h3> 2910 2911<p>When configured using --with-mem-debug flag (off by default), libxml2 uses 2912a set of memory allocation debugging routines keeping track of all allocated 2913blocks and the location in the code where the routine was called. A couple of 2914other debugging routines allow to dump the memory allocated infos to a file 2915or call a specific routine when a given block number is allocated:</p> 2916<ul> 2917 <li><a 2918 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMallocLoc()</a> 2919 <a 2920 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlReallocLoc()</a> 2921 and <a 2922 href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemStrdupLoc()</a> 2923 are the memory debugging replacement allocation routines</li> 2924 <li><a href="http://xmlsoft.org/html/libxml-xmlmemory.html">xmlMemoryDump 2925 ()</a> dumps all the informations about the allocated memory block lefts 2926 in the <code>.memdump</code> file</li> 2927</ul> 2928 2929<p>When developing libxml2 memory debug is enabled, the tests programs call 2930xmlMemoryDump () and the "make test" regression tests will check for any 2931memory leak during the full regression test sequence, this helps a lot 2932ensuring that libxml2 does not leak memory and bullet proof memory 2933allocations use (some libc implementations are known to be far too permissive 2934resulting in major portability problems!).</p> 2935 2936<p>If the .memdump reports a leak, it displays the allocation function and 2937also tries to give some informations about the content and structure of the 2938allocated blocks left. This is sufficient in most cases to find the culprit, 2939but not always. Assuming the allocation problem is reproducible, it is 2940possible to find more easily:</p> 2941<ol> 2942 <li>write down the block number xxxx not allocated</li> 2943 <li>export the environment variable XML_MEM_BREAKPOINT=xxxx , the easiest 2944 when using GDB is to simply give the command 2945 <p><code>set environment XML_MEM_BREAKPOINT xxxx</code></p> 2946 <p>before running the program.</p> 2947 </li> 2948 <li>run the program under a debugger and set a breakpoint on 2949 xmlMallocBreakpoint() a specific function called when this precise block 2950 is allocated</li> 2951 <li>when the breakpoint is reached you can then do a fine analysis of the 2952 allocation an step to see the condition resulting in the missing 2953 deallocation.</li> 2954</ol> 2955 2956<p>I used to use a commercial tool to debug libxml2 memory problems but after 2957noticing that it was not detecting memory leaks that simple mechanism was 2958used and proved extremely efficient until now. Lately I have also used <a 2959href="http://developer.kde.org/~sewardj/">valgrind</a> with quite some 2960success, it is tied to the i386 architecture since it works by emulating the 2961processor and instruction set, it is slow but extremely efficient, i.e. it 2962spot memory usage errors in a very precise way.</p> 2963 2964<h3><a name="General4">General memory requirements</a></h3> 2965 2966<p>How much libxml2 memory require ? It's hard to tell in average it depends 2967of a number of things:</p> 2968<ul> 2969 <li>the parser itself should work in a fixed amount of memory, except for 2970 information maintained about the stacks of names and entities locations. 2971 The I/O and encoding handlers will probably account for a few KBytes. 2972 This is true for both the XML and HTML parser (though the HTML parser 2973 need more state).</li> 2974 <li>If you are generating the DOM tree then memory requirements will grow 2975 nearly linear with the size of the data. In general for a balanced 2976 textual document the internal memory requirement is about 4 times the 2977 size of the UTF8 serialization of this document (example the XML-1.0 2978 recommendation is a bit more of 150KBytes and takes 650KBytes of main 2979 memory when parsed). Validation will add a amount of memory required for 2980 maintaining the external Dtd state which should be linear with the 2981 complexity of the content model defined by the Dtd</li> 2982 <li>If you need to work with fixed memory requirements or don't need the 2983 full DOM tree then using the <a href="xmlreader.html">xmlReader 2984 interface</a> is probably the best way to proceed, it still allows to 2985 validate or operate on subset of the tree if needed.</li> 2986 <li>If you don't care about the advanced features of libxml2 like 2987 validation, DOM, XPath or XPointer, don't use entities, need to work with 2988 fixed memory requirements, and try to get the fastest parsing possible 2989 then the SAX interface should be used, but it has known restrictions.</li> 2990</ul> 2991 2992<p></p> 2993 2994<h2><a name="Encodings">Encodings support</a></h2> 2995 2996<p>Table of Content:</p> 2997<ol> 2998 <li><a href="encoding.html#What">What does internationalization support 2999 mean ?</a></li> 3000 <li><a href="encoding.html#internal">The internal encoding, how and 3001 why</a></li> 3002 <li><a href="encoding.html#implemente">How is it implemented ?</a></li> 3003 <li><a href="encoding.html#Default">Default supported encodings</a></li> 3004 <li><a href="encoding.html#extend">How to extend the existing 3005 support</a></li> 3006</ol> 3007 3008<h3><a name="What">What does internationalization support mean ?</a></h3> 3009 3010<p>If you are not really familiar with Internationalization (usual shortcut 3011is I18N) , Unicode, characters and glyphs, I suggest you read a <a 3012href="http://www.tbray.org/ongoing/When/200x/2003/04/06/Unicode">presentation</a> 3013by Tim Bray on Unicode and why you should care about it.</p> 3014 3015<p>XML was designed from the start to allow the support of any character set 3016by using Unicode. Any conformant XML parser has to support the UTF-8 and 3017UTF-16 default encodings which can both express the full unicode ranges. UTF8 3018is a variable length encoding whose greatest points are to reuse the same 3019encoding for ASCII and to save space for Western encodings, but it is a bit 3020more complex to handle in practice. UTF-16 use 2 bytes per character (and 3021sometimes combines two pairs), it makes implementation easier, but looks a 3022bit overkill for Western languages encoding. Moreover the XML specification 3023allows the document to be encoded in other encodings at the condition that 3024they are clearly labeled as such. For example the following is a wellformed 3025XML document encoded in ISO-8859-1 and using accentuated letters that we 3026French like for both markup and content:</p> 3027<pre><?xml version="1.0" encoding="ISO-8859-1"?> 3028<tr�s>l�</tr�s></pre> 3029 3030<p>Having internationalization support in libxml2 means the following:</p> 3031<ul> 3032 <li>the document is properly parsed</li> 3033 <li>informations about it's encoding are saved</li> 3034 <li>it can be modified</li> 3035 <li>it can be saved in its original encoding</li> 3036 <li>it can also be saved in another encoding supported by libxml2 (for 3037 example straight UTF8 or even an ASCII form)</li> 3038</ul> 3039 3040<p>Another very important point is that the whole libxml2 API, with the 3041exception of a few routines to read with a specific encoding or save to a 3042specific encoding, is completely agnostic about the original encoding of the 3043document.</p> 3044 3045<p>It should be noted too that the HTML parser embedded in libxml2 now obey 3046the same rules too, the following document will be (as of 2.2.2) handled in 3047an internationalized fashion by libxml2 too:</p> 3048<pre><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" 3049 "http://www.w3.org/TR/REC-html40/loose.dtd"> 3050<html lang="fr"> 3051<head> 3052 <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"> 3053</head> 3054<body> 3055<p>W3C cr�e des standards pour le Web.</body> 3056</html></pre> 3057 3058<h3><a name="internal">The internal encoding, how and why</a></h3> 3059 3060<p>One of the core decisions was to force all documents to be converted to a 3061default internal encoding, and that encoding to be UTF-8, here are the 3062rationales for those choices:</p> 3063<ul> 3064 <li>keeping the native encoding in the internal form would force the libxml 3065 users (or the code associated) to be fully aware of the encoding of the 3066 original document, for examples when adding a text node to a document, 3067 the content would have to be provided in the document encoding, i.e. the 3068 client code would have to check it before hand, make sure it's conformant 3069 to the encoding, etc ... Very hard in practice, though in some specific 3070 cases this may make sense.</li> 3071 <li>the second decision was which encoding. From the XML spec only UTF8 and 3072 UTF16 really makes sense as being the two only encodings for which there 3073 is mandatory support. UCS-4 (32 bits fixed size encoding) could be 3074 considered an intelligent choice too since it's a direct Unicode mapping 3075 support. I selected UTF-8 on the basis of efficiency and compatibility 3076 with surrounding software: 3077 <ul> 3078 <li>UTF-8 while a bit more complex to convert from/to (i.e. slightly 3079 more costly to import and export CPU wise) is also far more compact 3080 than UTF-16 (and UCS-4) for a majority of the documents I see it used 3081 for right now (RPM RDF catalogs, advogato data, various configuration 3082 file formats, etc.) and the key point for today's computer 3083 architecture is efficient uses of caches. If one nearly double the 3084 memory requirement to store the same amount of data, this will trash 3085 caches (main memory/external caches/internal caches) and my take is 3086 that this harms the system far more than the CPU requirements needed 3087 for the conversion to UTF-8</li> 3088 <li>Most of libxml2 version 1 users were using it with straight ASCII 3089 most of the time, doing the conversion with an internal encoding 3090 requiring all their code to be rewritten was a serious show-stopper 3091 for using UTF-16 or UCS-4.</li> 3092 <li>UTF-8 is being used as the de-facto internal encoding standard for 3093 related code like the <a href="http://www.pango.org/">pango</a> 3094 upcoming Gnome text widget, and a lot of Unix code (yet another place 3095 where Unix programmer base takes a different approach from Microsoft 3096 - they are using UTF-16)</li> 3097 </ul> 3098 </li> 3099</ul> 3100 3101<p>What does this mean in practice for the libxml2 user:</p> 3102<ul> 3103 <li>xmlChar, the libxml2 data type is a byte, those bytes must be assembled 3104 as UTF-8 valid strings. The proper way to terminate an xmlChar * string 3105 is simply to append 0 byte, as usual.</li> 3106 <li>One just need to make sure that when using chars outside the ASCII set, 3107 the values has been properly converted to UTF-8</li> 3108</ul> 3109 3110<h3><a name="implemente">How is it implemented ?</a></h3> 3111 3112<p>Let's describe how all this works within libxml, basically the I18N 3113(internationalization) support get triggered only during I/O operation, i.e. 3114when reading a document or saving one. Let's look first at the reading 3115sequence:</p> 3116<ol> 3117 <li>when a document is processed, we usually don't know the encoding, a 3118 simple heuristic allows to detect UTF-16 and UCS-4 from encodings where 3119 the ASCII range (0-0x7F) maps with ASCII</li> 3120 <li>the xml declaration if available is parsed, including the encoding 3121 declaration. At that point, if the autodetected encoding is different 3122 from the one declared a call to xmlSwitchEncoding() is issued.</li> 3123 <li>If there is no encoding declaration, then the input has to be in either 3124 UTF-8 or UTF-16, if it is not then at some point when processing the 3125 input, the converter/checker of UTF-8 form will raise an encoding error. 3126 You may end-up with a garbled document, or no document at all ! Example: 3127 <pre>~/XML -> /xmllint err.xml 3128err.xml:1: error: Input is not proper UTF-8, indicate encoding ! 3129<tr�s>l�</tr�s> 3130 ^ 3131err.xml:1: error: Bytes: 0xE8 0x73 0x3E 0x6C 3132<tr�s>l�</tr�s> 3133 ^</pre> 3134 </li> 3135 <li>xmlSwitchEncoding() does an encoding name lookup, canonicalize it, and 3136 then search the default registered encoding converters for that encoding. 3137 If it's not within the default set and iconv() support has been compiled 3138 it, it will ask iconv for such an encoder. If this fails then the parser 3139 will report an error and stops processing: 3140 <pre>~/XML -> /xmllint err2.xml 3141err2.xml:1: error: Unsupported encoding UnsupportedEnc 3142<?xml version="1.0" encoding="UnsupportedEnc"?> 3143 ^</pre> 3144 </li> 3145 <li>From that point the encoder processes progressively the input (it is 3146 plugged as a front-end to the I/O module) for that entity. It captures 3147 and converts on-the-fly the document to be parsed to UTF-8. The parser 3148 itself just does UTF-8 checking of this input and process it 3149 transparently. The only difference is that the encoding information has 3150 been added to the parsing context (more precisely to the input 3151 corresponding to this entity).</li> 3152 <li>The result (when using DOM) is an internal form completely in UTF-8 3153 with just an encoding information on the document node.</li> 3154</ol> 3155 3156<p>Ok then what happens when saving the document (assuming you 3157collected/built an xmlDoc DOM like structure) ? It depends on the function 3158called, xmlSaveFile() will just try to save in the original encoding, while 3159xmlSaveFileTo() and xmlSaveFileEnc() can optionally save to a given 3160encoding:</p> 3161<ol> 3162 <li>if no encoding is given, libxml2 will look for an encoding value 3163 associated to the document and if it exists will try to save to that 3164 encoding, 3165 <p>otherwise everything is written in the internal form, i.e. UTF-8</p> 3166 </li> 3167 <li>so if an encoding was specified, either at the API level or on the 3168 document, libxml2 will again canonicalize the encoding name, lookup for a 3169 converter in the registered set or through iconv. If not found the 3170 function will return an error code</li> 3171 <li>the converter is placed before the I/O buffer layer, as another kind of 3172 buffer, then libxml2 will simply push the UTF-8 serialization to through 3173 that buffer, which will then progressively be converted and pushed onto 3174 the I/O layer.</li> 3175 <li>It is possible that the converter code fails on some input, for example 3176 trying to push an UTF-8 encoded Chinese character through the UTF-8 to 3177 ISO-8859-1 converter won't work. Since the encoders are progressive they 3178 will just report the error and the number of bytes converted, at that 3179 point libxml2 will decode the offending character, remove it from the 3180 buffer and replace it with the associated charRef encoding &#123; and 3181 resume the conversion. This guarantees that any document will be saved 3182 without losses (except for markup names where this is not legal, this is 3183 a problem in the current version, in practice avoid using non-ascii 3184 characters for tag or attribute names). A special "ascii" encoding name 3185 is used to save documents to a pure ascii form can be used when 3186 portability is really crucial</li> 3187</ol> 3188 3189<p>Here are a few examples based on the same test document:</p> 3190<pre>~/XML -> /xmllint isolat1 3191<?xml version="1.0" encoding="ISO-8859-1"?> 3192<tr�s>l�</tr�s> 3193~/XML -> /xmllint --encode UTF-8 isolat1 3194<?xml version="1.0" encoding="UTF-8"?> 3195<très>l� �</très> 3196~/XML -> </pre> 3197 3198<p>The same processing is applied (and reuse most of the code) for HTML I18N 3199processing. Looking up and modifying the content encoding is a bit more 3200difficult since it is located in a <meta> tag under the <head>, 3201so a couple of functions htmlGetMetaEncoding() and htmlSetMetaEncoding() have 3202been provided. The parser also attempts to switch encoding on the fly when 3203detecting such a tag on input. Except for that the processing is the same 3204(and again reuses the same code).</p> 3205 3206<h3><a name="Default">Default supported encodings</a></h3> 3207 3208<p>libxml2 has a set of default converters for the following encodings 3209(located in encoding.c):</p> 3210<ol> 3211 <li>UTF-8 is supported by default (null handlers)</li> 3212 <li>UTF-16, both little and big endian</li> 3213 <li>ISO-Latin-1 (ISO-8859-1) covering most western languages</li> 3214 <li>ASCII, useful mostly for saving</li> 3215 <li>HTML, a specific handler for the conversion of UTF-8 to ASCII with HTML 3216 predefined entities like &copy; for the Copyright sign.</li> 3217</ol> 3218 3219<p>More over when compiled on an Unix platform with iconv support the full 3220set of encodings supported by iconv can be instantly be used by libxml. On a 3221linux machine with glibc-2.1 the list of supported encodings and aliases fill 32223 full pages, and include UCS-4, the full set of ISO-Latin encodings, and the 3223various Japanese ones.</p> 3224 3225<h4>Encoding aliases</h4> 3226 3227<p>From 2.2.3, libxml2 has support to register encoding names aliases. The 3228goal is to be able to parse document whose encoding is supported but where 3229the name differs (for example from the default set of names accepted by 3230iconv). The following functions allow to register and handle new aliases for 3231existing encodings. Once registered libxml2 will automatically lookup the 3232aliases when handling a document:</p> 3233<ul> 3234 <li>int xmlAddEncodingAlias(const char *name, const char *alias);</li> 3235 <li>int xmlDelEncodingAlias(const char *alias);</li> 3236 <li>const char * xmlGetEncodingAlias(const char *alias);</li> 3237 <li>void xmlCleanupEncodingAliases(void);</li> 3238</ul> 3239 3240<h3><a name="extend">How to extend the existing support</a></h3> 3241 3242<p>Well adding support for new encoding, or overriding one of the encoders 3243(assuming it is buggy) should not be hard, just write input and output 3244conversion routines to/from UTF-8, and register them using 3245xmlNewCharEncodingHandler(name, xxxToUTF8, UTF8Toxxx), and they will be 3246called automatically if the parser(s) encounter such an encoding name 3247(register it uppercase, this will help). The description of the encoders, 3248their arguments and expected return values are described in the encoding.h 3249header.</p> 3250 3251<p>A quick note on the topic of subverting the parser to use a different 3252internal encoding than UTF-8, in some case people will absolutely want to 3253keep the internal encoding different, I think it's still possible (but the 3254encoding must be compliant with ASCII on the same subrange) though I didn't 3255tried it. The key is to override the default conversion routines (by 3256registering null encoders/decoders for your charsets), and bypass the UTF-8 3257checking of the parser by setting the parser context charset 3258(ctxt->charset) to something different than XML_CHAR_ENCODING_UTF8, but 3259there is no guarantee that this will work. You may also have some troubles 3260saving back.</p> 3261 3262<p>Basically proper I18N support is important, this requires at least 3263libxml-2.0.0, but a lot of features and corrections are really available only 3264starting 2.2.</p> 3265 3266<h2><a name="IO">I/O Interfaces</a></h2> 3267 3268<p>Table of Content:</p> 3269<ol> 3270 <li><a href="#General1">General overview</a></li> 3271 <li><a href="#basic">The basic buffer type</a></li> 3272 <li><a href="#Input">Input I/O handlers</a></li> 3273 <li><a href="#Output">Output I/O handlers</a></li> 3274 <li><a href="#entities">The entities loader</a></li> 3275 <li><a href="#Example2">Example of customized I/O</a></li> 3276</ol> 3277 3278<h3><a name="General1">General overview</a></h3> 3279 3280<p>The module <code><a 3281href="http://xmlsoft.org/html/libxml-xmlio.html">xmlIO.h</a></code> provides 3282the interfaces to the libxml2 I/O system. This consists of 4 main parts:</p> 3283<ul> 3284 <li>Entities loader, this is a routine which tries to fetch the entities 3285 (files) based on their PUBLIC and SYSTEM identifiers. The default loader 3286 don't look at the public identifier since libxml2 do not maintain a 3287 catalog. You can redefine you own entity loader by using 3288 <code>xmlGetExternalEntityLoader()</code> and 3289 <code>xmlSetExternalEntityLoader()</code>. <a href="#entities">Check the 3290 example</a>.</li> 3291 <li>Input I/O buffers which are a commodity structure used by the parser(s) 3292 input layer to handle fetching the informations to feed the parser. This 3293 provides buffering and is also a placeholder where the encoding 3294 converters to UTF8 are piggy-backed.</li> 3295 <li>Output I/O buffers are similar to the Input ones and fulfill similar 3296 task but when generating a serialization from a tree.</li> 3297 <li>A mechanism to register sets of I/O callbacks and associate them with 3298 specific naming schemes like the protocol part of the URIs. 3299 <p>This affect the default I/O operations and allows to use specific I/O 3300 handlers for certain names.</p> 3301 </li> 3302</ul> 3303 3304<p>The general mechanism used when loading http://rpmfind.net/xml.html for 3305example in the HTML parser is the following:</p> 3306<ol> 3307 <li>The default entity loader calls <code>xmlNewInputFromFile()</code> with 3308 the parsing context and the URI string.</li> 3309 <li>the URI string is checked against the existing registered handlers 3310 using their match() callback function, if the HTTP module was compiled 3311 in, it is registered and its match() function will succeeds</li> 3312 <li>the open() function of the handler is called and if successful will 3313 return an I/O Input buffer</li> 3314 <li>the parser will the start reading from this buffer and progressively 3315 fetch information from the resource, calling the read() function of the 3316 handler until the resource is exhausted</li> 3317 <li>if an encoding change is detected it will be installed on the input 3318 buffer, providing buffering and efficient use of the conversion 3319 routines</li> 3320 <li>once the parser has finished, the close() function of the handler is 3321 called once and the Input buffer and associated resources are 3322 deallocated.</li> 3323</ol> 3324 3325<p>The user defined callbacks are checked first to allow overriding of the 3326default libxml2 I/O routines.</p> 3327 3328<h3><a name="basic">The basic buffer type</a></h3> 3329 3330<p>All the buffer manipulation handling is done using the 3331<code>xmlBuffer</code> type define in <code><a 3332href="http://xmlsoft.org/html/libxml-tree.html">tree.h</a> </code>which is a 3333resizable memory buffer. The buffer allocation strategy can be selected to be 3334either best-fit or use an exponential doubling one (CPU vs. memory use 3335trade-off). The values are <code>XML_BUFFER_ALLOC_EXACT</code> and 3336<code>XML_BUFFER_ALLOC_DOUBLEIT</code>, and can be set individually or on a 3337system wide basis using <code>xmlBufferSetAllocationScheme()</code>. A number 3338of functions allows to manipulate buffers with names starting with the 3339<code>xmlBuffer...</code> prefix.</p> 3340 3341<h3><a name="Input">Input I/O handlers</a></h3> 3342 3343<p>An Input I/O handler is a simple structure 3344<code>xmlParserInputBuffer</code> containing a context associated to the 3345resource (file descriptor, or pointer to a protocol handler), the read() and 3346close() callbacks to use and an xmlBuffer. And extra xmlBuffer and a charset 3347encoding handler are also present to support charset conversion when 3348needed.</p> 3349 3350<h3><a name="Output">Output I/O handlers</a></h3> 3351 3352<p>An Output handler <code>xmlOutputBuffer</code> is completely similar to an 3353Input one except the callbacks are write() and close().</p> 3354 3355<h3><a name="entities">The entities loader</a></h3> 3356 3357<p>The entity loader resolves requests for new entities and create inputs for 3358the parser. Creating an input from a filename or an URI string is done 3359through the xmlNewInputFromFile() routine. The default entity loader do not 3360handle the PUBLIC identifier associated with an entity (if any). So it just 3361calls xmlNewInputFromFile() with the SYSTEM identifier (which is mandatory in 3362XML).</p> 3363 3364<p>If you want to hook up a catalog mechanism then you simply need to 3365override the default entity loader, here is an example:</p> 3366<pre>#include <libxml/xmlIO.h> 3367 3368xmlExternalEntityLoader defaultLoader = NULL; 3369 3370xmlParserInputPtr 3371xmlMyExternalEntityLoader(const char *URL, const char *ID, 3372 xmlParserCtxtPtr ctxt) { 3373 xmlParserInputPtr ret; 3374 const char *fileID = NULL; 3375 /* lookup for the fileID depending on ID */ 3376 3377 ret = xmlNewInputFromFile(ctxt, fileID); 3378 if (ret != NULL) 3379 return(ret); 3380 if (defaultLoader != NULL) 3381 ret = defaultLoader(URL, ID, ctxt); 3382 return(ret); 3383} 3384 3385int main(..) { 3386 ... 3387 3388 /* 3389 * Install our own entity loader 3390 */ 3391 defaultLoader = xmlGetExternalEntityLoader(); 3392 xmlSetExternalEntityLoader(xmlMyExternalEntityLoader); 3393 3394 ... 3395}</pre> 3396 3397<h3><a name="Example2">Example of customized I/O</a></h3> 3398 3399<p>This example come from <a href="http://xmlsoft.org/messages/0708.html">a 3400real use case</a>, xmlDocDump() closes the FILE * passed by the application 3401and this was a problem. The <a 3402href="http://xmlsoft.org/messages/0711.html">solution</a> was to redefine a 3403new output handler with the closing call deactivated:</p> 3404<ol> 3405 <li>First define a new I/O output allocator where the output don't close 3406 the file: 3407 <pre>xmlOutputBufferPtr 3408xmlOutputBufferCreateOwn(FILE *file, xmlCharEncodingHandlerPtr encoder) { 3409����xmlOutputBufferPtr ret; 3410���� 3411����if (xmlOutputCallbackInitialized == 0) 3412��������xmlRegisterDefaultOutputCallbacks(); 3413 3414����if (file == NULL) return(NULL); 3415����ret = xmlAllocOutputBuffer(encoder); 3416����if (ret != NULL) { 3417��������ret->context = file; 3418��������ret->writecallback = xmlFileWrite; 3419��������ret->closecallback = NULL; /* No close callback */ 3420����} 3421����return(ret); 3422} </pre> 3423 </li> 3424 <li>And then use it to save the document: 3425 <pre>FILE *f; 3426xmlOutputBufferPtr output; 3427xmlDocPtr doc; 3428int res; 3429 3430f = ... 3431doc = .... 3432 3433output = xmlOutputBufferCreateOwn(f, NULL); 3434res = xmlSaveFileTo(output, doc, NULL); 3435 </pre> 3436 </li> 3437</ol> 3438 3439<h2><a name="Catalog">Catalog support</a></h2> 3440 3441<p>Table of Content:</p> 3442<ol> 3443 <li><a href="General2">General overview</a></li> 3444 <li><a href="#definition">The definition</a></li> 3445 <li><a href="#Simple">Using catalogs</a></li> 3446 <li><a href="#Some">Some examples</a></li> 3447 <li><a href="#reference">How to tune catalog usage</a></li> 3448 <li><a href="#validate">How to debug catalog processing</a></li> 3449 <li><a href="#Declaring">How to create and maintain catalogs</a></li> 3450 <li><a href="#implemento">The implementor corner quick review of the 3451 API</a></li> 3452 <li><a href="#Other">Other resources</a></li> 3453</ol> 3454 3455<h3><a name="General2">General overview</a></h3> 3456 3457<p>What is a catalog? Basically it's a lookup mechanism used when an entity 3458(a file or a remote resource) references another entity. The catalog lookup 3459is inserted between the moment the reference is recognized by the software 3460(XML parser, stylesheet processing, or even images referenced for inclusion 3461in a rendering) and the time where loading that resource is actually 3462started.</p> 3463 3464<p>It is basically used for 3 things:</p> 3465<ul> 3466 <li>mapping from "logical" names, the public identifiers and a more 3467 concrete name usable for download (and URI). For example it can associate 3468 the logical name 3469 <p>"-//OASIS//DTD DocBook XML V4.1.2//EN"</p> 3470 <p>of the DocBook 4.1.2 XML DTD with the actual URL where it can be 3471 downloaded</p> 3472 <p>http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd</p> 3473 </li> 3474 <li>remapping from a given URL to another one, like an HTTP indirection 3475 saying that 3476 <p>"http://www.oasis-open.org/committes/tr.xsl"</p> 3477 <p>should really be looked at</p> 3478 <p>"http://www.oasis-open.org/committes/entity/stylesheets/base/tr.xsl"</p> 3479 </li> 3480 <li>providing a local cache mechanism allowing to load the entities 3481 associated to public identifiers or remote resources, this is a really 3482 important feature for any significant deployment of XML or SGML since it 3483 allows to avoid the aleas and delays associated to fetching remote 3484 resources.</li> 3485</ul> 3486 3487<h3><a name="definition">The definitions</a></h3> 3488 3489<p>Libxml, as of 2.4.3 implements 2 kind of catalogs:</p> 3490<ul> 3491 <li>the older SGML catalogs, the official spec is SGML Open Technical 3492 Resolution TR9401:1997, but is better understood by reading <a 3493 href="http://www.jclark.com/sp/catalog.htm">the SP Catalog page</a> from 3494 James Clark. This is relatively old and not the preferred mode of 3495 operation of libxml.</li> 3496 <li><a href="http://www.oasis-open.org/committees/entity/spec.html">XML 3497 Catalogs</a> is far more flexible, more recent, uses an XML syntax and 3498 should scale quite better. This is the default option of libxml.</li> 3499</ul> 3500 3501<p></p> 3502 3503<h3><a name="Simple">Using catalog</a></h3> 3504 3505<p>In a normal environment libxml2 will by default check the presence of a 3506catalog in /etc/xml/catalog, and assuming it has been correctly populated, 3507the processing is completely transparent to the document user. To take a 3508concrete example, suppose you are authoring a DocBook document, this one 3509starts with the following DOCTYPE definition:</p> 3510<pre><?xml version='1.0'?> 3511<!DOCTYPE book PUBLIC "-//Norman Walsh//DTD DocBk XML V3.1.4//EN" 3512 "http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd"></pre> 3513 3514<p>When validating the document with libxml, the catalog will be 3515automatically consulted to lookup the public identifier "-//Norman Walsh//DTD 3516DocBk XML V3.1.4//EN" and the system identifier 3517"http://nwalsh.com/docbook/xml/3.1.4/db3xml.dtd", and if these entities have 3518been installed on your system and the catalogs actually point to them, libxml 3519will fetch them from the local disk.</p> 3520 3521<p style="font-size: 10pt"><strong>Note</strong>: Really don't use this 3522DOCTYPE example it's a really old version, but is fine as an example.</p> 3523 3524<p>Libxml2 will check the catalog each time that it is requested to load an 3525entity, this includes DTD, external parsed entities, stylesheets, etc ... If 3526your system is correctly configured all the authoring phase and processing 3527should use only local files, even if your document stays portable because it 3528uses the canonical public and system ID, referencing the remote document.</p> 3529 3530<h3><a name="Some">Some examples:</a></h3> 3531 3532<p>Here is a couple of fragments from XML Catalogs used in libxml2 early 3533regression tests in <code>test/catalogs</code> :</p> 3534<pre><?xml version="1.0"?> 3535<!DOCTYPE catalog PUBLIC 3536 "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" 3537 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"> 3538<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"> 3539 <public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN" 3540 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/> 3541...</pre> 3542 3543<p>This is the beginning of a catalog for DocBook 4.1.2, XML Catalogs are 3544written in XML, there is a specific namespace for catalog elements 3545"urn:oasis:names:tc:entity:xmlns:xml:catalog". The first entry in this 3546catalog is a <code>public</code> mapping it allows to associate a Public 3547Identifier with an URI.</p> 3548<pre>... 3549 <rewriteSystem systemIdStartString="http://www.oasis-open.org/docbook/" 3550 rewritePrefix="file:///usr/share/xml/docbook/"/> 3551...</pre> 3552 3553<p>A <code>rewriteSystem</code> is a very powerful instruction, it says that 3554any URI starting with a given prefix should be looked at another URI 3555constructed by replacing the prefix with an new one. In effect this acts like 3556a cache system for a full area of the Web. In practice it is extremely useful 3557with a file prefix if you have installed a copy of those resources on your 3558local system.</p> 3559<pre>... 3560<delegatePublic publicIdStartString="-//OASIS//DTD XML Catalog //" 3561 catalog="file:///usr/share/xml/docbook.xml"/> 3562<delegatePublic publicIdStartString="-//OASIS//ENTITIES DocBook XML" 3563 catalog="file:///usr/share/xml/docbook.xml"/> 3564<delegatePublic publicIdStartString="-//OASIS//DTD DocBook XML" 3565 catalog="file:///usr/share/xml/docbook.xml"/> 3566<delegateSystem systemIdStartString="http://www.oasis-open.org/docbook/" 3567 catalog="file:///usr/share/xml/docbook.xml"/> 3568<delegateURI uriStartString="http://www.oasis-open.org/docbook/" 3569 catalog="file:///usr/share/xml/docbook.xml"/> 3570...</pre> 3571 3572<p>Delegation is the core features which allows to build a tree of catalogs, 3573easier to maintain than a single catalog, based on Public Identifier, System 3574Identifier or URI prefixes it instructs the catalog software to look up 3575entries in another resource. This feature allow to build hierarchies of 3576catalogs, the set of entries presented should be sufficient to redirect the 3577resolution of all DocBook references to the specific catalog in 3578<code>/usr/share/xml/docbook.xml</code> this one in turn could delegate all 3579references for DocBook 4.2.1 to a specific catalog installed at the same time 3580as the DocBook resources on the local machine.</p> 3581 3582<h3><a name="reference">How to tune catalog usage:</a></h3> 3583 3584<p>The user can change the default catalog behaviour by redirecting queries 3585to its own set of catalogs, this can be done by setting the 3586<code>XML_CATALOG_FILES</code> environment variable to a list of catalogs, an 3587empty one should deactivate loading the default <code>/etc/xml/catalog</code> 3588default catalog</p> 3589 3590<h3><a name="validate">How to debug catalog processing:</a></h3> 3591 3592<p>Setting up the <code>XML_DEBUG_CATALOG</code> environment variable will 3593make libxml2 output debugging informations for each catalog operations, for 3594example:</p> 3595<pre>orchis:~/XML -> xmllint --memory --noout test/ent2 3596warning: failed to load external entity "title.xml" 3597orchis:~/XML -> export XML_DEBUG_CATALOG= 3598orchis:~/XML -> xmllint --memory --noout test/ent2 3599Failed to parse catalog /etc/xml/catalog 3600Failed to parse catalog /etc/xml/catalog 3601warning: failed to load external entity "title.xml" 3602Catalogs cleanup 3603orchis:~/XML -> </pre> 3604 3605<p>The test/ent2 references an entity, running the parser from memory makes 3606the base URI unavailable and the the "title.xml" entity cannot be loaded. 3607Setting up the debug environment variable allows to detect that an attempt is 3608made to load the <code>/etc/xml/catalog</code> but since it's not present the 3609resolution fails.</p> 3610 3611<p>But the most advanced way to debug XML catalog processing is to use the 3612<strong>xmlcatalog</strong> command shipped with libxml2, it allows to load 3613catalogs and make resolution queries to see what is going on. This is also 3614used for the regression tests:</p> 3615<pre>orchis:~/XML -> /xmlcatalog test/catalogs/docbook.xml \ 3616 "-//OASIS//DTD DocBook XML V4.1.2//EN" 3617http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd 3618orchis:~/XML -> </pre> 3619 3620<p>For debugging what is going on, adding one -v flags increase the verbosity 3621level to indicate the processing done (adding a second flag also indicate 3622what elements are recognized at parsing):</p> 3623<pre>orchis:~/XML -> /xmlcatalog -v test/catalogs/docbook.xml \ 3624 "-//OASIS//DTD DocBook XML V4.1.2//EN" 3625Parsing catalog test/catalogs/docbook.xml's content 3626Found public match -//OASIS//DTD DocBook XML V4.1.2//EN 3627http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd 3628Catalogs cleanup 3629orchis:~/XML -> </pre> 3630 3631<p>A shell interface is also available to debug and process multiple queries 3632(and for regression tests):</p> 3633<pre>orchis:~/XML -> /xmlcatalog -shell test/catalogs/docbook.xml \ 3634 "-//OASIS//DTD DocBook XML V4.1.2//EN" 3635> help 3636Commands available: 3637public PublicID: make a PUBLIC identifier lookup 3638system SystemID: make a SYSTEM identifier lookup 3639resolve PublicID SystemID: do a full resolver lookup 3640add 'type' 'orig' 'replace' : add an entry 3641del 'values' : remove values 3642dump: print the current catalog state 3643debug: increase the verbosity level 3644quiet: decrease the verbosity level 3645exit: quit the shell 3646> public "-//OASIS//DTD DocBook XML V4.1.2//EN" 3647http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd 3648> quit 3649orchis:~/XML -> </pre> 3650 3651<p>This should be sufficient for most debugging purpose, this was actually 3652used heavily to debug the XML Catalog implementation itself.</p> 3653 3654<h3><a name="Declaring">How to create and maintain</a> catalogs:</h3> 3655 3656<p>Basically XML Catalogs are XML files, you can either use XML tools to 3657manage them or use <strong>xmlcatalog</strong> for this. The basic step is 3658to create a catalog the -create option provide this facility:</p> 3659<pre>orchis:~/XML -> /xmlcatalog --create tst.xml 3660<?xml version="1.0"?> 3661<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" 3662 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"> 3663<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/> 3664orchis:~/XML -> </pre> 3665 3666<p>By default xmlcatalog does not overwrite the original catalog and save the 3667result on the standard output, this can be overridden using the -noout 3668option. The <code>-add</code> command allows to add entries in the 3669catalog:</p> 3670<pre>orchis:~/XML -> /xmlcatalog --noout --create --add "public" \ 3671 "-//OASIS//DTD DocBook XML V4.1.2//EN" \ 3672 http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd tst.xml 3673orchis:~/XML -> cat tst.xml 3674<?xml version="1.0"?> 3675<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" \ 3676 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"> 3677<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"> 3678<public publicId="-//OASIS//DTD DocBook XML V4.1.2//EN" 3679 uri="http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"/> 3680</catalog> 3681orchis:~/XML -> </pre> 3682 3683<p>The <code>-add</code> option will always take 3 parameters even if some of 3684the XML Catalog constructs (like nextCatalog) will have only a single 3685argument, just pass a third empty string, it will be ignored.</p> 3686 3687<p>Similarly the <code>-del</code> option remove matching entries from the 3688catalog:</p> 3689<pre>orchis:~/XML -> /xmlcatalog --del \ 3690 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" tst.xml 3691<?xml version="1.0"?> 3692<!DOCTYPE catalog PUBLIC "-//OASIS//DTD Entity Resolution XML Catalog V1.0//EN" 3693 "http://www.oasis-open.org/committees/entity/release/1.0/catalog.dtd"> 3694<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"/> 3695orchis:~/XML -> </pre> 3696 3697<p>The catalog is now empty. Note that the matching of <code>-del</code> is 3698exact and would have worked in a similar fashion with the Public ID 3699string.</p> 3700 3701<p>This is rudimentary but should be sufficient to manage a not too complex 3702catalog tree of resources.</p> 3703 3704<h3><a name="implemento">The implementor corner quick review of the 3705API:</a></h3> 3706 3707<p>First, and like for every other module of libxml, there is an 3708automatically generated <a href="html/libxml-catalog.html">API page for 3709catalog support</a>.</p> 3710 3711<p>The header for the catalog interfaces should be included as:</p> 3712<pre>#include <libxml/catalog.h></pre> 3713 3714<p>The API is voluntarily kept very simple. First it is not obvious that 3715applications really need access to it since it is the default behaviour of 3716libxml2 (Note: it is possible to completely override libxml2 default catalog 3717by using <a href="html/libxml-parser.html">xmlSetExternalEntityLoader</a> to 3718plug an application specific resolver).</p> 3719 3720<p>Basically libxml2 support 2 catalog lists:</p> 3721<ul> 3722 <li>the default one, global shared by all the application</li> 3723 <li>a per-document catalog, this one is built if the document uses the 3724 <code>oasis-xml-catalog</code> PIs to specify its own catalog list, it is 3725 associated to the parser context and destroyed when the parsing context 3726 is destroyed.</li> 3727</ul> 3728 3729<p>the document one will be used first if it exists.</p> 3730 3731<h4>Initialization routines:</h4> 3732 3733<p>xmlInitializeCatalog(), xmlLoadCatalog() and xmlLoadCatalogs() should be 3734used at startup to initialize the catalog, if the catalog should be 3735initialized with specific values xmlLoadCatalog() or xmlLoadCatalogs() 3736should be called before xmlInitializeCatalog() which would otherwise do a 3737default initialization first.</p> 3738 3739<p>The xmlCatalogAddLocal() call is used by the parser to grow the document 3740own catalog list if needed.</p> 3741 3742<h4>Preferences setup:</h4> 3743 3744<p>The XML Catalog spec requires the possibility to select default 3745preferences between public and system delegation, 3746xmlCatalogSetDefaultPrefer() allows this, xmlCatalogSetDefaults() and 3747xmlCatalogGetDefaults() allow to control if XML Catalogs resolution should 3748be forbidden, allowed for global catalog, for document catalog or both, the 3749default is to allow both.</p> 3750 3751<p>And of course xmlCatalogSetDebug() allows to generate debug messages 3752(through the xmlGenericError() mechanism).</p> 3753 3754<h4>Querying routines:</h4> 3755 3756<p>xmlCatalogResolve(), xmlCatalogResolveSystem(), xmlCatalogResolvePublic() 3757and xmlCatalogResolveURI() are relatively explicit if you read the XML 3758Catalog specification they correspond to section 7 algorithms, they should 3759also work if you have loaded an SGML catalog with a simplified semantic.</p> 3760 3761<p>xmlCatalogLocalResolve() and xmlCatalogLocalResolveURI() are the same but 3762operate on the document catalog list</p> 3763 3764<h4>Cleanup and Miscellaneous:</h4> 3765 3766<p>xmlCatalogCleanup() free-up the global catalog, xmlCatalogFreeLocal() is 3767the per-document equivalent.</p> 3768 3769<p>xmlCatalogAdd() and xmlCatalogRemove() are used to dynamically modify the 3770first catalog in the global list, and xmlCatalogDump() allows to dump a 3771catalog state, those routines are primarily designed for xmlcatalog, I'm not 3772sure that exposing more complex interfaces (like navigation ones) would be 3773really useful.</p> 3774 3775<p>The xmlParseCatalogFile() is a function used to load XML Catalog files, 3776it's similar as xmlParseFile() except it bypass all catalog lookups, it's 3777provided because this functionality may be useful for client tools.</p> 3778 3779<h4>threaded environments:</h4> 3780 3781<p>Since the catalog tree is built progressively, some care has been taken to 3782try to avoid troubles in multithreaded environments. The code is now thread 3783safe assuming that the libxml2 library has been compiled with threads 3784support.</p> 3785 3786<p></p> 3787 3788<h3><a name="Other">Other resources</a></h3> 3789 3790<p>The XML Catalog specification is relatively recent so there isn't much 3791literature to point at:</p> 3792<ul> 3793 <li>You can find a good rant from Norm Walsh about <a 3794 href="http://www.arbortext.com/Think_Tank/XML_Resources/Issue_Three/issue_three.html">the 3795 need for catalogs</a>, it provides a lot of context informations even if 3796 I don't agree with everything presented. Norm also wrote a more recent 3797 article <a 3798 href="http://wwws.sun.com/software/xml/developers/resolver/article/">XML 3799 entities and URI resolvers</a> describing them.</li> 3800 <li>An <a href="http://home.ccil.org/~cowan/XML/XCatalog.html">old XML 3801 catalog proposal</a> from John Cowan</li> 3802 <li>The <a href="http://www.rddl.org/">Resource Directory Description 3803 Language</a> (RDDL) another catalog system but more oriented toward 3804 providing metadata for XML namespaces.</li> 3805 <li>the page from the OASIS Technical <a 3806 href="http://www.oasis-open.org/committees/entity/">Committee on Entity 3807 Resolution</a> who maintains XML Catalog, you will find pointers to the 3808 specification update, some background and pointers to others tools 3809 providing XML Catalog support</li> 3810 <li>There is a <a href="buildDocBookCatalog">shell script</a> to generate 3811 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/ 3812 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on 3813 the resources found on the system. Otherwise it will just create 3814 ~/xmlcatalog and ~/dbkxmlcatalog and doing: 3815 <p><code>export XML_CATALOG_FILES=$HOME/xmlcatalog</code></p> 3816 <p>should allow to process DocBook documentations without requiring 3817 network accesses for the DTD or stylesheets</p> 3818 </li> 3819 <li>I have uploaded <a href="ftp://xmlsoft.org/test/dbk412catalog.tar.gz">a 3820 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems 3821 to work fine for me too</li> 3822 <li>The <a href="http://www.xmlsoft.org/xmlcatalog_man.html">xmlcatalog 3823 manual page</a></li> 3824</ul> 3825 3826<p>If you have suggestions for corrections or additions, simply contact 3827me:</p> 3828 3829<h2><a name="library">The parser interfaces</a></h2> 3830 3831<p>This section is directly intended to help programmers getting bootstrapped 3832using the XML tollkit from the C language. It is not intended to be 3833extensive. I hope the automatically generated documents will provide the 3834completeness required, but as a separate set of documents. The interfaces of 3835the XML parser are by principle low level, Those interested in a higher level 3836API should <a href="#DOM">look at DOM</a>.</p> 3837 3838<p>The <a href="html/libxml-parser.html">parser interfaces for XML</a> are 3839separated from the <a href="html/libxml-htmlparser.html">HTML parser 3840interfaces</a>. Let's have a look at how the XML parser can be called:</p> 3841 3842<h3><a name="Invoking">Invoking the parser : the pull method</a></h3> 3843 3844<p>Usually, the first thing to do is to read an XML input. The parser accepts 3845documents either from in-memory strings or from files. The functions are 3846defined in "parser.h":</p> 3847<dl> 3848 <dt><code>xmlDocPtr xmlParseMemory(char *buffer, int size);</code></dt> 3849 <dd><p>Parse a null-terminated string containing the document.</p> 3850 </dd> 3851</dl> 3852<dl> 3853 <dt><code>xmlDocPtr xmlParseFile(const char *filename);</code></dt> 3854 <dd><p>Parse an XML document contained in a (possibly compressed) 3855 file.</p> 3856 </dd> 3857</dl> 3858 3859<p>The parser returns a pointer to the document structure (or NULL in case of 3860failure).</p> 3861 3862<h3 id="Invoking1">Invoking the parser: the push method</h3> 3863 3864<p>In order for the application to keep the control when the document is 3865being fetched (which is common for GUI based programs) libxml2 provides a 3866push interface, too, as of version 1.8.3. Here are the interface 3867functions:</p> 3868<pre>xmlParserCtxtPtr xmlCreatePushParserCtxt(xmlSAXHandlerPtr sax, 3869 void *user_data, 3870 const char *chunk, 3871 int size, 3872 const char *filename); 3873int xmlParseChunk (xmlParserCtxtPtr ctxt, 3874 const char *chunk, 3875 int size, 3876 int terminate);</pre> 3877 3878<p>and here is a simple example showing how to use the interface:</p> 3879<pre> FILE *f; 3880 3881 f = fopen(filename, "r"); 3882 if (f != NULL) { 3883 int res, size = 1024; 3884 char chars[1024]; 3885 xmlParserCtxtPtr ctxt; 3886 3887 res = fread(chars, 1, 4, f); 3888 if (res > 0) { 3889 ctxt = xmlCreatePushParserCtxt(NULL, NULL, 3890 chars, res, filename); 3891 while ((res = fread(chars, 1, size, f)) > 0) { 3892 xmlParseChunk(ctxt, chars, res, 0); 3893 } 3894 xmlParseChunk(ctxt, chars, 0, 1); 3895 doc = ctxt->myDoc; 3896 xmlFreeParserCtxt(ctxt); 3897 } 3898 }</pre> 3899 3900<p>The HTML parser embedded into libxml2 also has a push interface; the 3901functions are just prefixed by "html" rather than "xml".</p> 3902 3903<h3 id="Invoking2">Invoking the parser: the SAX interface</h3> 3904 3905<p>The tree-building interface makes the parser memory-hungry, first loading 3906the document in memory and then building the tree itself. Reading a document 3907without building the tree is possible using the SAX interfaces (see SAX.h and 3908<a href="http://www.daa.com.au/~james/gnome/xml-sax/xml-sax.html">James 3909Henstridge's documentation</a>). Note also that the push interface can be 3910limited to SAX: just use the two first arguments of 3911<code>xmlCreatePushParserCtxt()</code>.</p> 3912 3913<h3><a name="Building">Building a tree from scratch</a></h3> 3914 3915<p>The other way to get an XML tree in memory is by building it. Basically 3916there is a set of functions dedicated to building new elements. (These are 3917also described in <libxml/tree.h>.) For example, here is a piece of 3918code that produces the XML document used in the previous examples:</p> 3919<pre> #include <libxml/tree.h> 3920 xmlDocPtr doc; 3921 xmlNodePtr tree, subtree; 3922 3923 doc = xmlNewDoc("1.0"); 3924 doc->children = xmlNewDocNode(doc, NULL, "EXAMPLE", NULL); 3925 xmlSetProp(doc->children, "prop1", "gnome is great"); 3926 xmlSetProp(doc->children, "prop2", "& linux too"); 3927 tree = xmlNewChild(doc->children, NULL, "head", NULL); 3928 subtree = xmlNewChild(tree, NULL, "title", "Welcome to Gnome"); 3929 tree = xmlNewChild(doc->children, NULL, "chapter", NULL); 3930 subtree = xmlNewChild(tree, NULL, "title", "The Linux adventure"); 3931 subtree = xmlNewChild(tree, NULL, "p", "bla bla bla ..."); 3932 subtree = xmlNewChild(tree, NULL, "image", NULL); 3933 xmlSetProp(subtree, "href", "linus.gif");</pre> 3934 3935<p>Not really rocket science ...</p> 3936 3937<h3><a name="Traversing">Traversing the tree</a></h3> 3938 3939<p>Basically by <a href="html/libxml-tree.html">including "tree.h"</a> your 3940code has access to the internal structure of all the elements of the tree. 3941The names should be somewhat simple like <strong>parent</strong>, 3942<strong>children</strong>, <strong>next</strong>, <strong>prev</strong>, 3943<strong>properties</strong>, etc... For example, still with the previous 3944example:</p> 3945<pre><code>doc->children->children->children</code></pre> 3946 3947<p>points to the title element,</p> 3948<pre>doc->children->children->next->children->children</pre> 3949 3950<p>points to the text node containing the chapter title "The Linux 3951adventure".</p> 3952 3953<p><strong>NOTE</strong>: XML allows <em>PI</em>s and <em>comments</em> to be 3954present before the document root, so <code>doc->children</code> may point 3955to an element which is not the document Root Element; a function 3956<code>xmlDocGetRootElement()</code> was added for this purpose.</p> 3957 3958<h3><a name="Modifying">Modifying the tree</a></h3> 3959 3960<p>Functions are provided for reading and writing the document content. Here 3961is an excerpt from the <a href="html/libxml-tree.html">tree API</a>:</p> 3962<dl> 3963 <dt><code>xmlAttrPtr xmlSetProp(xmlNodePtr node, const xmlChar *name, const 3964 xmlChar *value);</code></dt> 3965 <dd><p>This sets (or changes) an attribute carried by an ELEMENT node. 3966 The value can be NULL.</p> 3967 </dd> 3968</dl> 3969<dl> 3970 <dt><code>const xmlChar *xmlGetProp(xmlNodePtr node, const xmlChar 3971 *name);</code></dt> 3972 <dd><p>This function returns a pointer to new copy of the property 3973 content. Note that the user must deallocate the result.</p> 3974 </dd> 3975</dl> 3976 3977<p>Two functions are provided for reading and writing the text associated 3978with elements:</p> 3979<dl> 3980 <dt><code>xmlNodePtr xmlStringGetNodeList(xmlDocPtr doc, const xmlChar 3981 *value);</code></dt> 3982 <dd><p>This function takes an "external" string and converts it to one 3983 text node or possibly to a list of entity and text nodes. All 3984 non-predefined entity references like &Gnome; will be stored 3985 internally as entity nodes, hence the result of the function may not be 3986 a single node.</p> 3987 </dd> 3988</dl> 3989<dl> 3990 <dt><code>xmlChar *xmlNodeListGetString(xmlDocPtr doc, xmlNodePtr list, int 3991 inLine);</code></dt> 3992 <dd><p>This function is the inverse of 3993 <code>xmlStringGetNodeList()</code>. It generates a new string 3994 containing the content of the text and entity nodes. Note the extra 3995 argument inLine. If this argument is set to 1, the function will expand 3996 entity references. For example, instead of returning the &Gnome; 3997 XML encoding in the string, it will substitute it with its value (say, 3998 "GNU Network Object Model Environment").</p> 3999 </dd> 4000</dl> 4001 4002<h3><a name="Saving">Saving a tree</a></h3> 4003 4004<p>Basically 3 options are possible:</p> 4005<dl> 4006 <dt><code>void xmlDocDumpMemory(xmlDocPtr cur, xmlChar**mem, int 4007 *size);</code></dt> 4008 <dd><p>Returns a buffer into which the document has been saved.</p> 4009 </dd> 4010</dl> 4011<dl> 4012 <dt><code>extern void xmlDocDump(FILE *f, xmlDocPtr doc);</code></dt> 4013 <dd><p>Dumps a document to an open file descriptor.</p> 4014 </dd> 4015</dl> 4016<dl> 4017 <dt><code>int xmlSaveFile(const char *filename, xmlDocPtr cur);</code></dt> 4018 <dd><p>Saves the document to a file. In this case, the compression 4019 interface is triggered if it has been turned on.</p> 4020 </dd> 4021</dl> 4022 4023<h3><a name="Compressio">Compression</a></h3> 4024 4025<p>The library transparently handles compression when doing file-based 4026accesses. The level of compression on saves can be turned on either globally 4027or individually for one file:</p> 4028<dl> 4029 <dt><code>int xmlGetDocCompressMode (xmlDocPtr doc);</code></dt> 4030 <dd><p>Gets the document compression ratio (0-9).</p> 4031 </dd> 4032</dl> 4033<dl> 4034 <dt><code>void xmlSetDocCompressMode (xmlDocPtr doc, int mode);</code></dt> 4035 <dd><p>Sets the document compression ratio.</p> 4036 </dd> 4037</dl> 4038<dl> 4039 <dt><code>int xmlGetCompressMode(void);</code></dt> 4040 <dd><p>Gets the default compression ratio.</p> 4041 </dd> 4042</dl> 4043<dl> 4044 <dt><code>void xmlSetCompressMode(int mode);</code></dt> 4045 <dd><p>Sets the default compression ratio.</p> 4046 </dd> 4047</dl> 4048 4049<h2><a name="Entities">Entities or no entities</a></h2> 4050 4051<p>Entities in principle are similar to simple C macros. An entity defines an 4052abbreviation for a given string that you can reuse many times throughout the 4053content of your document. Entities are especially useful when a given string 4054may occur frequently within a document, or to confine the change needed to a 4055document to a restricted area in the internal subset of the document (at the 4056beginning). Example:</p> 4057<pre>1 <?xml version="1.0"?> 40582 <!DOCTYPE EXAMPLE SYSTEM "example.dtd" [ 40593 <!ENTITY xml "Extensible Markup Language"> 40604 ]> 40615 <EXAMPLE> 40626 &xml; 40637 </EXAMPLE></pre> 4064 4065<p>Line 3 declares the xml entity. Line 6 uses the xml entity, by prefixing 4066its name with '&' and following it by ';' without any spaces added. There 4067are 5 predefined entities in libxml2 allowing you to escape characters with 4068predefined meaning in some parts of the xml document content: 4069<strong>&lt;</strong> for the character '<', <strong>&gt;</strong> 4070for the character '>', <strong>&apos;</strong> for the character ''', 4071<strong>&quot;</strong> for the character '"', and 4072<strong>&amp;</strong> for the character '&'.</p> 4073 4074<p>One of the problems related to entities is that you may want the parser to 4075substitute an entity's content so that you can see the replacement text in 4076your application. Or you may prefer to keep entity references as such in the 4077content to be able to save the document back without losing this usually 4078precious information (if the user went through the pain of explicitly 4079defining entities, he may have a a rather negative attitude if you blindly 4080substitute them as saving time). The <a 4081href="html/libxml-parser.html#xmlSubstituteEntitiesDefault">xmlSubstituteEntitiesDefault()</a> 4082function allows you to check and change the behaviour, which is to not 4083substitute entities by default.</p> 4084 4085<p>Here is the DOM tree built by libxml2 for the previous document in the 4086default case:</p> 4087<pre>/gnome/src/gnome-xml -> /xmllint --debug test/ent1 4088DOCUMENT 4089version=1.0 4090 ELEMENT EXAMPLE 4091 TEXT 4092 content= 4093 ENTITY_REF 4094 INTERNAL_GENERAL_ENTITY xml 4095 content=Extensible Markup Language 4096 TEXT 4097 content=</pre> 4098 4099<p>And here is the result when substituting entities:</p> 4100<pre>/gnome/src/gnome-xml -> /tester --debug --noent test/ent1 4101DOCUMENT 4102version=1.0 4103 ELEMENT EXAMPLE 4104 TEXT 4105 content= Extensible Markup Language</pre> 4106 4107<p>So, entities or no entities? Basically, it depends on your use case. I 4108suggest that you keep the non-substituting default behaviour and avoid using 4109entities in your XML document or data if you are not willing to handle the 4110entity references elements in the DOM tree.</p> 4111 4112<p>Note that at save time libxml2 enforces the conversion of the predefined 4113entities where necessary to prevent well-formedness problems, and will also 4114transparently replace those with chars (i.e. it will not generate entity 4115reference elements in the DOM tree or call the reference() SAX callback when 4116finding them in the input).</p> 4117 4118<p><span style="background-color: #FF0000">WARNING</span>: handling entities 4119on top of the libxml2 SAX interface is difficult!!! If you plan to use 4120non-predefined entities in your documents, then the learning curve to handle 4121then using the SAX API may be long. If you plan to use complex documents, I 4122strongly suggest you consider using the DOM interface instead and let libxml 4123deal with the complexity rather than trying to do it yourself.</p> 4124 4125<h2><a name="Namespaces">Namespaces</a></h2> 4126 4127<p>The libxml2 library implements <a 4128href="http://www.w3.org/TR/REC-xml-names/">XML namespaces</a> support by 4129recognizing namespace constructs in the input, and does namespace lookup 4130automatically when building the DOM tree. A namespace declaration is 4131associated with an in-memory structure and all elements or attributes within 4132that namespace point to it. Hence testing the namespace is a simple and fast 4133equality operation at the user level.</p> 4134 4135<p>I suggest that people using libxml2 use a namespace, and declare it in the 4136root element of their document as the default namespace. Then they don't need 4137to use the prefix in the content but we will have a basis for future semantic 4138refinement and merging of data from different sources. This doesn't increase 4139the size of the XML output significantly, but significantly increases its 4140value in the long-term. Example:</p> 4141<pre><mydoc xmlns="http://mydoc.example.org/schemas/"> 4142 <elem1>...</elem1> 4143 <elem2>...</elem2> 4144</mydoc></pre> 4145 4146<p>The namespace value has to be an absolute URL, but the URL doesn't have to 4147point to any existing resource on the Web. It will bind all the element and 4148attributes with that URL. I suggest to use an URL within a domain you 4149control, and that the URL should contain some kind of version information if 4150possible. For example, <code>"http://www.gnome.org/gnumeric/1.0/"</code> is a 4151good namespace scheme.</p> 4152 4153<p>Then when you load a file, make sure that a namespace carrying the 4154version-independent prefix is installed on the root element of your document, 4155and if the version information don't match something you know, warn the user 4156and be liberal in what you accept as the input. Also do *not* try to base 4157namespace checking on the prefix value. <foo:text> may be exactly the 4158same as <bar:text> in another document. What really matters is the URI 4159associated with the element or the attribute, not the prefix string (which is 4160just a shortcut for the full URI). In libxml, element and attributes have an 4161<code>ns</code> field pointing to an xmlNs structure detailing the namespace 4162prefix and its URI.</p> 4163 4164<p>@@Interfaces@@</p> 4165<pre>xmlNodePtr node; 4166if(!strncmp(node->name,"mytag",5) 4167 && node->ns 4168 && !strcmp(node->ns->href,"http://www.mysite.com/myns/1.0")) { 4169 ... 4170}</pre> 4171 4172<p>Usually people object to using namespaces together with validity checking. 4173I will try to make sure that using namespaces won't break validity checking, 4174so even if you plan to use or currently are using validation I strongly 4175suggest adding namespaces to your document. A default namespace scheme 4176<code>xmlns="http://...."</code> should not break validity even on less 4177flexible parsers. Using namespaces to mix and differentiate content coming 4178from multiple DTDs will certainly break current validation schemes. To check 4179such documents one needs to use schema-validation, which is supported in 4180libxml2 as well. See <a href="http://www.relaxng.org/">relagx-ng</a> and <a 4181href="http://www.w3c.org/XML/Schema">w3c-schema</a>.</p> 4182 4183<h2><a name="Upgrading">Upgrading 1.x code</a></h2> 4184 4185<p>Incompatible changes:</p> 4186 4187<p>Version 2 of libxml2 is the first version introducing serious backward 4188incompatible changes. The main goals were:</p> 4189<ul> 4190 <li>a general cleanup. A number of mistakes inherited from the very early 4191 versions couldn't be changed due to compatibility constraints. Example 4192 the "childs" element in the nodes.</li> 4193 <li>Uniformization of the various nodes, at least for their header and link 4194 parts (doc, parent, children, prev, next), the goal is a simpler 4195 programming model and simplifying the task of the DOM implementors.</li> 4196 <li>better conformances to the XML specification, for example version 1.x 4197 had an heuristic to try to detect ignorable white spaces. As a result the 4198 SAX event generated were ignorableWhitespace() while the spec requires 4199 character() in that case. This also mean that a number of DOM node 4200 containing blank text may populate the DOM tree which were not present 4201 before.</li> 4202</ul> 4203 4204<h3>How to fix libxml-1.x code:</h3> 4205 4206<p>So client code of libxml designed to run with version 1.x may have to be 4207changed to compile against version 2.x of libxml. Here is a list of changes 4208that I have collected, they may not be sufficient, so in case you find other 4209change which are required, <a href="mailto:Daniel.Veillard@w3.org">drop me a 4210mail</a>:</p> 4211<ol> 4212 <li>The package name have changed from libxml to libxml2, the library name 4213 is now -lxml2 . There is a new xml2-config script which should be used to 4214 select the right parameters libxml2</li> 4215 <li>Node <strong>childs</strong> field has been renamed 4216 <strong>children</strong> so s/childs/children/g should be applied 4217 (probability of having "childs" anywhere else is close to 0+</li> 4218 <li>The document don't have anymore a <strong>root</strong> element it has 4219 been replaced by <strong>children</strong> and usually you will get a 4220 list of element here. For example a Dtd element for the internal subset 4221 and it's declaration may be found in that list, as well as processing 4222 instructions or comments found before or after the document root element. 4223 Use <strong>xmlDocGetRootElement(doc)</strong> to get the root element of 4224 a document. Alternatively if you are sure to not reference DTDs nor have 4225 PIs or comments before or after the root element 4226 s/->root/->children/g will probably do it.</li> 4227 <li>The white space issue, this one is more complex, unless special case of 4228 validating parsing, the line breaks and spaces usually used for indenting 4229 and formatting the document content becomes significant. So they are 4230 reported by SAX and if your using the DOM tree, corresponding nodes are 4231 generated. Too approach can be taken: 4232 <ol> 4233 <li>lazy one, use the compatibility call 4234 <strong>xmlKeepBlanksDefault(0)</strong> but be aware that you are 4235 relying on a special (and possibly broken) set of heuristics of 4236 libxml to detect ignorable blanks. Don't complain if it breaks or 4237 make your application not 100% clean w.r.t. to it's input.</li> 4238 <li>the Right Way: change you code to accept possibly insignificant 4239 blanks characters, or have your tree populated with weird blank text 4240 nodes. You can spot them using the commodity function 4241 <strong>xmlIsBlankNode(node)</strong> returning 1 for such blank 4242 nodes.</li> 4243 </ol> 4244 <p>Note also that with the new default the output functions don't add any 4245 extra indentation when saving a tree in order to be able to round trip 4246 (read and save) without inflating the document with extra formatting 4247 chars.</p> 4248 </li> 4249 <li>The include path has changed to $prefix/libxml/ and the includes 4250 themselves uses this new prefix in includes instructions... If you are 4251 using (as expected) the 4252 <pre>xml2-config --cflags</pre> 4253 <p>output to generate you compile commands this will probably work out of 4254 the box</p> 4255 </li> 4256 <li>xmlDetectCharEncoding takes an extra argument indicating the length in 4257 byte of the head of the document available for character detection.</li> 4258</ol> 4259 4260<h3>Ensuring both libxml-1.x and libxml-2.x compatibility</h3> 4261 4262<p>Two new version of libxml (1.8.11) and libxml2 (2.3.4) have been released 4263to allow smooth upgrade of existing libxml v1code while retaining 4264compatibility. They offers the following:</p> 4265<ol> 4266 <li>similar include naming, one should use 4267 <strong>#include<libxml/...></strong> in both cases.</li> 4268 <li>similar identifiers defined via macros for the child and root fields: 4269 respectively <strong>xmlChildrenNode</strong> and 4270 <strong>xmlRootNode</strong></li> 4271 <li>a new macro <strong>LIBXML_TEST_VERSION</strong> which should be 4272 inserted once in the client code</li> 4273</ol> 4274 4275<p>So the roadmap to upgrade your existing libxml applications is the 4276following:</p> 4277<ol> 4278 <li>install the libxml-1.8.8 (and libxml-devel-1.8.8) packages</li> 4279 <li>find all occurrences where the xmlDoc <strong>root</strong> field is 4280 used and change it to <strong>xmlRootNode</strong></li> 4281 <li>similarly find all occurrences where the xmlNode 4282 <strong>childs</strong> field is used and change it to 4283 <strong>xmlChildrenNode</strong></li> 4284 <li>add a <strong>LIBXML_TEST_VERSION</strong> macro somewhere in your 4285 <strong>main()</strong> or in the library init entry point</li> 4286 <li>Recompile, check compatibility, it should still work</li> 4287 <li>Change your configure script to look first for xml2-config and fall 4288 back using xml-config . Use the --cflags and --libs output of the command 4289 as the Include and Linking parameters needed to use libxml.</li> 4290 <li>install libxml2-2.3.x and libxml2-devel-2.3.x (libxml-1.8.y and 4291 libxml-devel-1.8.y can be kept simultaneously)</li> 4292 <li>remove your config.cache, relaunch your configuration mechanism, and 4293 recompile, if steps 2 and 3 were done right it should compile as-is</li> 4294 <li>Test that your application is still running correctly, if not this may 4295 be due to extra empty nodes due to formating spaces being kept in libxml2 4296 contrary to libxml1, in that case insert xmlKeepBlanksDefault(1) in your 4297 code before calling the parser (next to 4298 <strong>LIBXML_TEST_VERSION</strong> is a fine place).</li> 4299</ol> 4300 4301<p>Following those steps should work. It worked for some of my own code.</p> 4302 4303<p>Let me put some emphasis on the fact that there is far more changes from 4304libxml 1.x to 2.x than the ones you may have to patch for. The overall code 4305has been considerably cleaned up and the conformance to the XML specification 4306has been drastically improved too. Don't take those changes as an excuse to 4307not upgrade, it may cost a lot on the long term ...</p> 4308 4309<h2><a name="Thread">Thread safety</a></h2> 4310 4311<p>Starting with 2.4.7, libxml2 makes provisions to ensure that concurrent 4312threads can safely work in parallel parsing different documents. There is 4313however a couple of things to do to ensure it:</p> 4314<ul> 4315 <li>configure the library accordingly using the --with-threads options</li> 4316 <li>call xmlInitParser() in the "main" thread before using any of the 4317 libxml2 API (except possibly selecting a different memory allocator)</li> 4318</ul> 4319 4320<p>Note that the thread safety cannot be ensured for multiple threads sharing 4321the same document, the locking must be done at the application level, libxml 4322exports a basic mutex and reentrant mutexes API in <libxml/threads.h>. 4323The parts of the library checked for thread safety are:</p> 4324<ul> 4325 <li>concurrent loading</li> 4326 <li>file access resolution</li> 4327 <li>catalog access</li> 4328 <li>catalog building</li> 4329 <li>entities lookup/accesses</li> 4330 <li>validation</li> 4331 <li>global variables per-thread override</li> 4332 <li>memory handling</li> 4333</ul> 4334 4335<p>XPath is supposed to be thread safe now, but this wasn't tested 4336seriously.</p> 4337 4338<h2><a name="DOM"></a><a name="Principles">DOM Principles</a></h2> 4339 4340<p><a href="http://www.w3.org/DOM/">DOM</a> stands for the <em>Document 4341Object Model</em>; this is an API for accessing XML or HTML structured 4342documents. Native support for DOM in Gnome is on the way (module gnome-dom), 4343and will be based on gnome-xml. This will be a far cleaner interface to 4344manipulate XML files within Gnome since it won't expose the internal 4345structure.</p> 4346 4347<p>The current DOM implementation on top of libxml2 is the <a 4348href="http://cvs.gnome.org/lxr/source/gdome2/">gdome2 Gnome module</a>, this 4349is a full DOM interface, thanks to Paolo Casarini, check the <a 4350href="http://www.cs.unibo.it/~casarini/gdome2/">Gdome2 homepage</a> for more 4351informations.</p> 4352 4353<h2><a name="Example"></a><a name="real">A real example</a></h2> 4354 4355<p>Here is a real size example, where the actual content of the application 4356data is not kept in the DOM tree but uses internal structures. It is based on 4357a proposal to keep a database of jobs related to Gnome, with an XML based 4358storage structure. Here is an <a href="gjobs.xml">XML encoded jobs 4359base</a>:</p> 4360<pre><?xml version="1.0"?> 4361<gjob:Helping xmlns:gjob="http://www.gnome.org/some-location"> 4362 <gjob:Jobs> 4363 4364 <gjob:Job> 4365 <gjob:Project ID="3"/> 4366 <gjob:Application>GBackup</gjob:Application> 4367 <gjob:Category>Development</gjob:Category> 4368 4369 <gjob:Update> 4370 <gjob:Status>Open</gjob:Status> 4371 <gjob:Modified>Mon, 07 Jun 1999 20:27:45 -0400 MET DST</gjob:Modified> 4372 <gjob:Salary>USD 0.00</gjob:Salary> 4373 </gjob:Update> 4374 4375 <gjob:Developers> 4376 <gjob:Developer> 4377 </gjob:Developer> 4378 </gjob:Developers> 4379 4380 <gjob:Contact> 4381 <gjob:Person>Nathan Clemons</gjob:Person> 4382 <gjob:Email>nathan@windsofstorm.net</gjob:Email> 4383 <gjob:Company> 4384 </gjob:Company> 4385 <gjob:Organisation> 4386 </gjob:Organisation> 4387 <gjob:Webpage> 4388 </gjob:Webpage> 4389 <gjob:Snailmail> 4390 </gjob:Snailmail> 4391 <gjob:Phone> 4392 </gjob:Phone> 4393 </gjob:Contact> 4394 4395 <gjob:Requirements> 4396 The program should be released as free software, under the GPL. 4397 </gjob:Requirements> 4398 4399 <gjob:Skills> 4400 </gjob:Skills> 4401 4402 <gjob:Details> 4403 A GNOME based system that will allow a superuser to configure 4404 compressed and uncompressed files and/or file systems to be backed 4405 up with a supported media in the system. This should be able to 4406 perform via find commands generating a list of files that are passed 4407 to tar, dd, cpio, cp, gzip, etc., to be directed to the tape machine 4408 or via operations performed on the filesystem itself. Email 4409 notification and GUI status display very important. 4410 </gjob:Details> 4411 4412 </gjob:Job> 4413 4414 </gjob:Jobs> 4415</gjob:Helping></pre> 4416 4417<p>While loading the XML file into an internal DOM tree is a matter of 4418calling only a couple of functions, browsing the tree to gather the data and 4419generate the internal structures is harder, and more error prone.</p> 4420 4421<p>The suggested principle is to be tolerant with respect to the input 4422structure. For example, the ordering of the attributes is not significant, 4423the XML specification is clear about it. It's also usually a good idea not to 4424depend on the order of the children of a given node, unless it really makes 4425things harder. Here is some code to parse the information for a person:</p> 4426<pre>/* 4427 * A person record 4428 */ 4429typedef struct person { 4430 char *name; 4431 char *email; 4432 char *company; 4433 char *organisation; 4434 char *smail; 4435 char *webPage; 4436 char *phone; 4437} person, *personPtr; 4438 4439/* 4440 * And the code needed to parse it 4441 */ 4442personPtr parsePerson(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) { 4443 personPtr ret = NULL; 4444 4445DEBUG("parsePerson\n"); 4446 /* 4447 * allocate the struct 4448 */ 4449 ret = (personPtr) malloc(sizeof(person)); 4450 if (ret == NULL) { 4451 fprintf(stderr,"out of memory\n"); 4452 return(NULL); 4453 } 4454 memset(ret, 0, sizeof(person)); 4455 4456 /* We don't care what the top level element name is */ 4457 cur = cur->xmlChildrenNode; 4458 while (cur != NULL) { 4459 if ((!strcmp(cur->name, "Person")) && (cur->ns == ns)) 4460 ret->name = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1); 4461 if ((!strcmp(cur->name, "Email")) && (cur->ns == ns)) 4462 ret->email = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1); 4463 cur = cur->next; 4464 } 4465 4466 return(ret); 4467}</pre> 4468 4469<p>Here are a couple of things to notice:</p> 4470<ul> 4471 <li>Usually a recursive parsing style is the more convenient one: XML data 4472 is by nature subject to repetitive constructs and usually exhibits highly 4473 structured patterns.</li> 4474 <li>The two arguments of type <em>xmlDocPtr</em> and <em>xmlNsPtr</em>, 4475 i.e. the pointer to the global XML document and the namespace reserved to 4476 the application. Document wide information are needed for example to 4477 decode entities and it's a good coding practice to define a namespace for 4478 your application set of data and test that the element and attributes 4479 you're analyzing actually pertains to your application space. This is 4480 done by a simple equality test (cur->ns == ns).</li> 4481 <li>To retrieve text and attributes value, you can use the function 4482 <em>xmlNodeListGetString</em> to gather all the text and entity reference 4483 nodes generated by the DOM output and produce an single text string.</li> 4484</ul> 4485 4486<p>Here is another piece of code used to parse another level of the 4487structure:</p> 4488<pre>#include <libxml/tree.h> 4489/* 4490 * a Description for a Job 4491 */ 4492typedef struct job { 4493 char *projectID; 4494 char *application; 4495 char *category; 4496 personPtr contact; 4497 int nbDevelopers; 4498 personPtr developers[100]; /* using dynamic alloc is left as an exercise */ 4499} job, *jobPtr; 4500 4501/* 4502 * And the code needed to parse it 4503 */ 4504jobPtr parseJob(xmlDocPtr doc, xmlNsPtr ns, xmlNodePtr cur) { 4505 jobPtr ret = NULL; 4506 4507DEBUG("parseJob\n"); 4508 /* 4509 * allocate the struct 4510 */ 4511 ret = (jobPtr) malloc(sizeof(job)); 4512 if (ret == NULL) { 4513 fprintf(stderr,"out of memory\n"); 4514 return(NULL); 4515 } 4516 memset(ret, 0, sizeof(job)); 4517 4518 /* We don't care what the top level element name is */ 4519 cur = cur->xmlChildrenNode; 4520 while (cur != NULL) { 4521 4522 if ((!strcmp(cur->name, "Project")) && (cur->ns == ns)) { 4523 ret->projectID = xmlGetProp(cur, "ID"); 4524 if (ret->projectID == NULL) { 4525 fprintf(stderr, "Project has no ID\n"); 4526 } 4527 } 4528 if ((!strcmp(cur->name, "Application")) && (cur->ns == ns)) 4529 ret->application = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1); 4530 if ((!strcmp(cur->name, "Category")) && (cur->ns == ns)) 4531 ret->category = xmlNodeListGetString(doc, cur->xmlChildrenNode, 1); 4532 if ((!strcmp(cur->name, "Contact")) && (cur->ns == ns)) 4533 ret->contact = parsePerson(doc, ns, cur); 4534 cur = cur->next; 4535 } 4536 4537 return(ret); 4538}</pre> 4539 4540<p>Once you are used to it, writing this kind of code is quite simple, but 4541boring. Ultimately, it could be possible to write stubbers taking either C 4542data structure definitions, a set of XML examples or an XML DTD and produce 4543the code needed to import and export the content between C data and XML 4544storage. This is left as an exercise to the reader :-)</p> 4545 4546<p>Feel free to use <a href="example/gjobread.c">the code for the full C 4547parsing example</a> as a template, it is also available with Makefile in the 4548Gnome CVS base under gnome-xml/example</p> 4549 4550<h2><a name="Contributi">Contributions</a></h2> 4551<ul> 4552 <li>Bjorn Reese, William Brack and Thomas Broyer have provided a number of 4553 patches, Gary Pennington worked on the validation API, threading support 4554 and Solaris port.</li> 4555 <li>John Fleck helps maintaining the documentation and man pages.</li> 4556 <li><a href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the 4557 maintainer of the Windows port, <a 4558 href="http://www.zlatkovic.com/projects/libxml/index.html">he provides 4559 binaries</a></li> 4560 <li><a href="mailto:Gary.Pennington@sun.com">Gary Pennington</a> provides 4561 <a href="http://garypennington.net/libxml2/">Solaris binaries</a></li> 4562 <li><a 4563 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt 4564 Sergeant</a> developed <a 4565 href="http://axkit.org/download/">XML::LibXSLT</a>, a Perl wrapper for 4566 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML 4567 application server</a></li> 4568 <li><a href="mailto:fnatter@gmx.net">Felix Natter</a> and <a 4569 href="mailto:geertk@ai.rug.nl">Geert Kloosterman</a> provide <a 4570 href="libxml-doc.el">an emacs module</a> to lookup libxml(2) functions 4571 documentation</li> 4572 <li><a href="mailto:sherwin@nlm.nih.gov">Ziying Sherwin</a> provided <a 4573 href="http://xmlsoft.org/messages/0488.html">man pages</a></li> 4574 <li>there is a module for <a 4575 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support 4576 in OpenNSD/AOLServer</a></li> 4577 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provided the 4578 first version of libxml/libxslt <a 4579 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li> 4580 <li>Petr Kozelka provides <a 4581 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue 4582 libxml2</a> with Kylix and Delphi and other Pascal compilers</li> 4583 <li><a href="mailto:aleksey@aleksey.com">Aleksey Sanin</a> implemented the 4584 <a href="http://www.w3.org/Signature/">XML Canonicalization and XML 4585 Digital Signature</a> <a 4586 href="http://www.aleksey.com/xmlsec/">implementations for libxml2</a></li> 4587 <li><a href="mailto:Steve.Ball@zveno.com">Steve Ball</a>, <a 4588 href="http://www.zveno.com/">Zveno</a> and contributors maintain <a 4589 href="http://tclxml.sourceforge.net/">tcl bindings for libxml2 and 4590 libxslt</a>, as well as <a 4591 href="http://tclxml.sf.net/tkxmllint.html">tkxmllint</a> a GUI for 4592 xmllint and <a href="http://tclxml.sf.net/tkxsltproc.html">tkxsltproc</a> 4593 a GUI for xsltproc.</li> 4594</ul> 4595 4596<p></p> 4597</body> 4598</html> 4599
