1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 /* 19 * $Id: PrefixResolverDefault.java 468655 2006-10-28 07:12:06Z minchau $ 20 */ 21 package org.apache.xml.utils; 22 23 import org.w3c.dom.NamedNodeMap; 24 import org.w3c.dom.Node; 25 26 /** 27 * This class implements a generic PrefixResolver that 28 * can be used to perform prefix-to-namespace lookup 29 * for the XPath object. 30 * @xsl.usage general 31 */ 32 public class PrefixResolverDefault implements PrefixResolver 33 { 34 35 /** 36 * The context to resolve the prefix from, if the context 37 * is not given. 38 */ 39 Node m_context; 40 41 /** 42 * Construct a PrefixResolverDefault object. 43 * @param xpathExpressionContext The context from 44 * which XPath expression prefixes will be resolved. 45 * Warning: This will not work correctly if xpathExpressionContext 46 * is an attribute node. 47 */ PrefixResolverDefault(Node xpathExpressionContext)48 public PrefixResolverDefault(Node xpathExpressionContext) 49 { 50 m_context = xpathExpressionContext; 51 } 52 53 /** 54 * Given a namespace, get the corrisponding prefix. This assumes that 55 * the PrevixResolver hold's it's own namespace context, or is a namespace 56 * context itself. 57 * @param prefix Prefix to resolve. 58 * @return Namespace that prefix resolves to, or null if prefix 59 * is not bound. 60 */ getNamespaceForPrefix(String prefix)61 public String getNamespaceForPrefix(String prefix) 62 { 63 return getNamespaceForPrefix(prefix, m_context); 64 } 65 66 /** 67 * Given a namespace, get the corrisponding prefix. 68 * Warning: This will not work correctly if namespaceContext 69 * is an attribute node. 70 * @param prefix Prefix to resolve. 71 * @param namespaceContext Node from which to start searching for a 72 * xmlns attribute that binds a prefix to a namespace. 73 * @return Namespace that prefix resolves to, or null if prefix 74 * is not bound. 75 */ getNamespaceForPrefix(String prefix, org.w3c.dom.Node namespaceContext)76 public String getNamespaceForPrefix(String prefix, 77 org.w3c.dom.Node namespaceContext) 78 { 79 80 Node parent = namespaceContext; 81 String namespace = null; 82 83 if (prefix.equals("xml")) 84 { 85 namespace = Constants.S_XMLNAMESPACEURI; 86 } 87 else 88 { 89 int type; 90 91 while ((null != parent) && (null == namespace) 92 && (((type = parent.getNodeType()) == Node.ELEMENT_NODE) 93 || (type == Node.ENTITY_REFERENCE_NODE))) 94 { 95 if (type == Node.ELEMENT_NODE) 96 { 97 if (parent.getNodeName().indexOf(prefix+":") == 0) 98 return parent.getNamespaceURI(); 99 NamedNodeMap nnm = parent.getAttributes(); 100 101 for (int i = 0; i < nnm.getLength(); i++) 102 { 103 Node attr = nnm.item(i); 104 String aname = attr.getNodeName(); 105 boolean isPrefix = aname.startsWith("xmlns:"); 106 107 if (isPrefix || aname.equals("xmlns")) 108 { 109 int index = aname.indexOf(':'); 110 String p = isPrefix ? aname.substring(index + 1) : ""; 111 112 if (p.equals(prefix)) 113 { 114 namespace = attr.getNodeValue(); 115 116 break; 117 } 118 } 119 } 120 } 121 122 parent = parent.getParentNode(); 123 } 124 } 125 126 return namespace; 127 } 128 129 /** 130 * Return the base identifier. 131 * 132 * @return null 133 */ getBaseIdentifier()134 public String getBaseIdentifier() 135 { 136 return null; 137 } 138 /** 139 * @see PrefixResolver#handlesNullPrefixes() 140 */ handlesNullPrefixes()141 public boolean handlesNullPrefixes() { 142 return false; 143 } 144 145 } 146