1/*
2 * xlink.c : implementation of the hyperlinks detection module
3 *           This version supports both XML XLinks and HTML simple links
4 *
5 * See Copyright for the status of this software.
6 *
7 * daniel@veillard.com
8 */
9
10
11#define IN_LIBXML
12#include "libxml.h"
13
14#ifdef LIBXML_XPTR_ENABLED
15#include <string.h> /* for memset() only */
16#ifdef HAVE_CTYPE_H
17#include <ctype.h>
18#endif
19#ifdef HAVE_STDLIB_H
20#include <stdlib.h>
21#endif
22#ifdef HAVE_SYS_STAT_H
23#include <sys/stat.h>
24#endif
25#ifdef HAVE_FCNTL_H
26#include <fcntl.h>
27#endif
28#ifdef HAVE_UNISTD_H
29#include <unistd.h>
30#endif
31#ifdef HAVE_ZLIB_H
32#include <zlib.h>
33#endif
34
35#include <libxml/xmlmemory.h>
36#include <libxml/tree.h>
37#include <libxml/parser.h>
38#include <libxml/valid.h>
39#include <libxml/xlink.h>
40#include <libxml/globals.h>
41
42#define XLINK_NAMESPACE (BAD_CAST "http://www.w3.org/1999/xlink/namespace/")
43#define XHTML_NAMESPACE (BAD_CAST "http://www.w3.org/1999/xhtml/")
44
45/****************************************************************
46 *								*
47 *           Default setting and related functions		*
48 *								*
49 ****************************************************************/
50
51static xlinkHandlerPtr xlinkDefaultHandler = NULL;
52static xlinkNodeDetectFunc	xlinkDefaultDetect = NULL;
53
54/**
55 * xlinkGetDefaultHandler:
56 *
57 * Get the default xlink handler.
58 *
59 * Returns the current xlinkHandlerPtr value.
60 */
61xlinkHandlerPtr
62xlinkGetDefaultHandler(void) {
63    return(xlinkDefaultHandler);
64}
65
66
67/**
68 * xlinkSetDefaultHandler:
69 * @handler:  the new value for the xlink handler block
70 *
71 * Set the default xlink handlers
72 */
73void
74xlinkSetDefaultHandler(xlinkHandlerPtr handler) {
75    xlinkDefaultHandler = handler;
76}
77
78/**
79 * xlinkGetDefaultDetect:
80 *
81 * Get the default xlink detection routine
82 *
83 * Returns the current function or NULL;
84 */
85xlinkNodeDetectFunc
86xlinkGetDefaultDetect	(void) {
87    return(xlinkDefaultDetect);
88}
89
90/**
91 * xlinkSetDefaultDetect:
92 * @func: pointer to the new detection routine.
93 *
94 * Set the default xlink detection routine
95 */
96void
97xlinkSetDefaultDetect	(xlinkNodeDetectFunc func) {
98    xlinkDefaultDetect = func;
99}
100
101/****************************************************************
102 *								*
103 *                  The detection routines			*
104 *								*
105 ****************************************************************/
106
107
108/**
109 * xlinkIsLink:
110 * @doc:  the document containing the node
111 * @node:  the node pointer itself
112 *
113 * Check whether the given node carries the attributes needed
114 * to be a link element (or is one of the linking elements issued
115 * from the (X)HTML DtDs).
116 * This routine don't try to do full checking of the link validity
117 * but tries to detect and return the appropriate link type.
118 *
119 * Returns the xlinkType of the node (XLINK_TYPE_NONE if there is no
120 *         link detected.
121 */
122xlinkType
123xlinkIsLink	(xmlDocPtr doc, xmlNodePtr node) {
124    xmlChar *type = NULL, *role = NULL;
125    xlinkType ret = XLINK_TYPE_NONE;
126
127    if (node == NULL) return(XLINK_TYPE_NONE);
128    if (doc == NULL) doc = node->doc;
129    if ((doc != NULL) && (doc->type == XML_HTML_DOCUMENT_NODE)) {
130        /*
131	 * This is an HTML document.
132	 */
133    } else if ((node->ns != NULL) &&
134               (xmlStrEqual(node->ns->href, XHTML_NAMESPACE))) {
135	/*
136	 * !!!! We really need an IS_XHTML_ELEMENT function from HTMLtree.h @@@
137	 */
138        /*
139	 * This is an XHTML element within an XML document
140	 * Check whether it's one of the element able to carry links
141	 * and in that case if it holds the attributes.
142	 */
143    }
144
145    /*
146     * We don't prevent a-priori having XML Linking constructs on
147     * XHTML elements
148     */
149    type = xmlGetNsProp(node, BAD_CAST"type", XLINK_NAMESPACE);
150    if (type != NULL) {
151	if (xmlStrEqual(type, BAD_CAST "simple")) {
152            ret = XLINK_TYPE_SIMPLE;
153	} if (xmlStrEqual(type, BAD_CAST "extended")) {
154	    role = xmlGetNsProp(node, BAD_CAST "role", XLINK_NAMESPACE);
155	    if (role != NULL) {
156		xmlNsPtr xlink;
157		xlink = xmlSearchNs(doc, node, XLINK_NAMESPACE);
158		if (xlink == NULL) {
159		    /* Humm, fallback method */
160		    if (xmlStrEqual(role, BAD_CAST"xlink:external-linkset"))
161			ret = XLINK_TYPE_EXTENDED_SET;
162		} else {
163		    xmlChar buf[200];
164		    snprintf((char *) buf, sizeof(buf), "%s:external-linkset",
165			     (char *) xlink->prefix);
166                    buf[sizeof(buf) - 1] = 0;
167		    if (xmlStrEqual(role, buf))
168			ret = XLINK_TYPE_EXTENDED_SET;
169
170		}
171
172	    }
173	    ret = XLINK_TYPE_EXTENDED;
174	}
175    }
176
177    if (type != NULL) xmlFree(type);
178    if (role != NULL) xmlFree(role);
179    return(ret);
180}
181#endif /* LIBXML_XPTR_ENABLED */
182#define bottom_xlink
183#include "elfgcchack.h"
184