19f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/* 29f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Licensed to the Apache Software Foundation (ASF) under one 39f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * or more contributor license agreements. See the NOTICE file 49f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * distributed with this work for additional information 59f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * regarding copyright ownership. The ASF licenses this file 69f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * to you under the Apache License, Version 2.0 (the "License"); 79f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * you may not use this file except in compliance with the License. 89f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * You may obtain a copy of the License at 99f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 109f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * http://www.apache.org/licenses/LICENSE-2.0 119f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 129f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Unless required by applicable law or agreed to in writing, software 139f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * distributed under the License is distributed on an "AS IS" BASIS, 149f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 159f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * See the License for the specific language governing permissions and 169f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * limitations under the License. 179f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 189f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/* 199f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * $Id: XPathAPI.java 524807 2007-04-02 15:51:43Z zongaro $ 209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpackage org.apache.xpath; 229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport javax.xml.transform.TransformerException; 249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xml.utils.PrefixResolver; 269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xml.utils.PrefixResolverDefault; 279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.apache.xpath.objects.XObject; 289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.w3c.dom.Document; 309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.w3c.dom.Node; 319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.w3c.dom.NodeList; 329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonimport org.w3c.dom.traversal.NodeIterator; 339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson/** 359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * The methods in this class are convenience methods into the 369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * low-level XPath API. 379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * These functions tend to be a little slow, since a number of objects must be 389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * created for each evaluation. A faster way is to precompile the 399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPaths using the low-level API, and then just use the XPaths 409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * over and over. 419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * NOTE: In particular, each call to this method will create a new 439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPathContext, a new DTMManager... and thus a new DTM. That's very 449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * safe, since it guarantees that you're always processing against a 459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * fully up-to-date view of your document. But it's also portentially 469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * very expensive, since you're rebuilding the DTM every time. You should 479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * consider using an instance of CachedXPathAPI rather than these static 489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * methods. 499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see <a href="http://www.w3.org/TR/xpath">XPath Specification</a> 519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * */ 529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilsonpublic class XPathAPI 539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson{ 549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Use an XPath string to select a single node. XPath namespace 579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * prefixes are resolved from the context node, which may not 589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * be what you want (see the next method). 599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param contextNode The node to start searching from. 619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param str A valid XPath string. 629f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return The first node found that matches the XPath, or null. 639f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 649f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws TransformerException 659f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 669f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static Node selectSingleNode(Node contextNode, String str) 679f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws TransformerException 689f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 699f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return selectSingleNode(contextNode, str, contextNode); 709f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 719f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 729f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 739f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Use an XPath string to select a single node. 749f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPath namespace prefixes are resolved from the namespaceNode. 759f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 769f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param contextNode The node to start searching from. 779f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param str A valid XPath string. 789f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param namespaceNode The node from which prefixes in the XPath will be resolved to namespaces. 799f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return The first node found that matches the XPath, or null. 809f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 819f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws TransformerException 829f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 839f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static Node selectSingleNode( 849f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson Node contextNode, String str, Node namespaceNode) 859f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws TransformerException 869f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 879f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 889f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Have the XObject return its result as a NodeSetDTM. 899f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson NodeIterator nl = selectNodeIterator(contextNode, str, namespaceNode); 909f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 919f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Return the first node, or null 929f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return nl.nextNode(); 939f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 949f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 959f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 969f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Use an XPath string to select a nodelist. 979f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPath namespace prefixes are resolved from the contextNode. 989f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 999f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param contextNode The node to start searching from. 1009f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param str A valid XPath string. 1019f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return A NodeIterator, should never be null. 1029f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1039f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws TransformerException 1049f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1059f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static NodeIterator selectNodeIterator(Node contextNode, String str) 1069f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws TransformerException 1079f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1089f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return selectNodeIterator(contextNode, str, contextNode); 1099f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1109f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1119f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1129f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Use an XPath string to select a nodelist. 1139f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPath namespace prefixes are resolved from the namespaceNode. 1149f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1159f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param contextNode The node to start searching from. 1169f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param str A valid XPath string. 1179f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param namespaceNode The node from which prefixes in the XPath will be resolved to namespaces. 1189f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return A NodeIterator, should never be null. 1199f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws TransformerException 1219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static NodeIterator selectNodeIterator( 1239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson Node contextNode, String str, Node namespaceNode) 1249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws TransformerException 1259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Execute the XPath, and have it return the result 1289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson XObject list = eval(contextNode, str, namespaceNode); 1299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Have the XObject return its result as a NodeSetDTM. 1319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return list.nodeset(); 1329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Use an XPath string to select a nodelist. 1369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPath namespace prefixes are resolved from the contextNode. 1379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param contextNode The node to start searching from. 1399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param str A valid XPath string. 1409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return A NodeIterator, should never be null. 1419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws TransformerException 1439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static NodeList selectNodeList(Node contextNode, String str) 1459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws TransformerException 1469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return selectNodeList(contextNode, str, contextNode); 1489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Use an XPath string to select a nodelist. 1529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPath namespace prefixes are resolved from the namespaceNode. 1539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param contextNode The node to start searching from. 1559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param str A valid XPath string. 1569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param namespaceNode The node from which prefixes in the XPath will be resolved to namespaces. 1579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return A NodeIterator, should never be null. 1589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws TransformerException 1609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static NodeList selectNodeList( 1629f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson Node contextNode, String str, Node namespaceNode) 1639f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws TransformerException 1649f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1659f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1669f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Execute the XPath, and have it return the result 1679f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson XObject list = eval(contextNode, str, namespaceNode); 1689f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1699f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Return a NodeList. 1709f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return list.nodelist(); 1719f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1729f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1739f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1749f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Evaluate XPath string to an XObject. Using this method, 1759f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPath namespace prefixes will be resolved from the namespaceNode. 1769f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param contextNode The node to start searching from. 1779f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param str A valid XPath string. 1789f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return An XObject, which can be used to obtain a string, number, nodelist, etc, should never be null. 1799f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XObject 1809f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XNull 1819f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XBoolean 1829f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XNumber 1839f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XString 1849f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XRTreeFrag 1859f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 1869f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws TransformerException 1879f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 1889f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static XObject eval(Node contextNode, String str) 1899f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws TransformerException 1909f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 1919f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return eval(contextNode, str, contextNode); 1929f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 1939f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 1949f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 1959f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Evaluate XPath string to an XObject. 1969f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPath namespace prefixes are resolved from the namespaceNode. 1979f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * The implementation of this is a little slow, since it creates 1989f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * a number of objects each time it is called. This could be optimized 1999f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * to keep the same objects around, but then thread-safety issues would arise. 2009f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 2019f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param contextNode The node to start searching from. 2029f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param str A valid XPath string. 2039f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param namespaceNode The node from which prefixes in the XPath will be resolved to namespaces. 2049f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return An XObject, which can be used to obtain a string, number, nodelist, etc, should never be null. 2059f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XObject 2069f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XNull 2079f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XBoolean 2089f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XNumber 2099f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XString 2109f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XRTreeFrag 2119f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 2129f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws TransformerException 2139f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 2149f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static XObject eval(Node contextNode, String str, Node namespaceNode) 2159f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws TransformerException 2169f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 2179f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2189f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Since we don't have a XML Parser involved here, install some default support 2199f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // for things like namespaces, etc. 2209f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // (Changed from: XPathContext xpathSupport = new XPathContext(); 2219f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // because XPathContext is weak in a number of areas... perhaps 2229f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // XPathContext should be done away with.) 2239f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Create an XPathContext that doesn't support pushing and popping of 2249f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // variable resolution scopes. Sufficient for simple XPath 1.0 expressions. 2259f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson XPathContext xpathSupport = new XPathContext(false); 2269f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2279f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Create an object to resolve namespace prefixes. 2289f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // XPath namespaces are resolved from the input context node's document element 2299f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // if it is a root node, or else the current context node (for lack of a better 2309f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // resolution space, given the simplicity of this sample code). 2319f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson PrefixResolverDefault prefixResolver = new PrefixResolverDefault( 2329f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson (namespaceNode.getNodeType() == Node.DOCUMENT_NODE) 2339f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson ? ((Document) namespaceNode).getDocumentElement() : namespaceNode); 2349f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2359f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Create the XPath object. 2369f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson XPath xpath = new XPath(str, null, prefixResolver, XPath.SELECT, null); 2379f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2389f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Execute the XPath, and have it return the result 2399f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // return xpath.execute(xpathSupport, contextNode, prefixResolver); 2409f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson int ctxtNode = xpathSupport.getDTMHandleFromNode(contextNode); 2419f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2429f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return xpath.execute(xpathSupport, ctxtNode, prefixResolver); 2439f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 2449f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2459f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson /** 2469f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * Evaluate XPath string to an XObject. 2479f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * XPath namespace prefixes are resolved from the namespaceNode. 2489f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * The implementation of this is a little slow, since it creates 2499f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * a number of objects each time it is called. This could be optimized 2509f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * to keep the same objects around, but then thread-safety issues would arise. 2519f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 2529f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param contextNode The node to start searching from. 2539f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param str A valid XPath string. 2549f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @param prefixResolver Will be called if the parser encounters namespace 2559f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * prefixes, to resolve the prefixes to URLs. 2569f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @return An XObject, which can be used to obtain a string, number, nodelist, etc, should never be null. 2579f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XObject 2589f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XNull 2599f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XBoolean 2609f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XNumber 2619f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XString 2629f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @see org.apache.xpath.objects.XRTreeFrag 2639f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * 2649f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson * @throws TransformerException 2659f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson */ 2669f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson public static XObject eval( 2679f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson Node contextNode, String str, PrefixResolver prefixResolver) 2689f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson throws TransformerException 2699f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson { 2709f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2719f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Since we don't have a XML Parser involved here, install some default support 2729f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // for things like namespaces, etc. 2739f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // (Changed from: XPathContext xpathSupport = new XPathContext(); 2749f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // because XPathContext is weak in a number of areas... perhaps 2759f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // XPathContext should be done away with.) 2769f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Create the XPath object. 2779f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson XPath xpath = new XPath(str, null, prefixResolver, XPath.SELECT, null); 2789f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2799f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Create an XPathContext that doesn't support pushing and popping of 2809f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // variable resolution scopes. Sufficient for simple XPath 1.0 expressions. 2819f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson XPathContext xpathSupport = new XPathContext(false); 2829f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2839f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson // Execute the XPath, and have it return the result 2849f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson int ctxtNode = xpathSupport.getDTMHandleFromNode(contextNode); 2859f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson 2869f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson return xpath.execute(xpathSupport, ctxtNode, prefixResolver); 2879f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson } 2889f8118474e9513f7a5b7d2a05e4a0fb15d1a6569Jesse Wilson} 289