001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.commons.jxpath.ri.model.dom;
018
019 import java.util.ArrayList;
020 import java.util.List;
021
022 import org.apache.commons.jxpath.ri.QName;
023 import org.apache.commons.jxpath.ri.model.NodeIterator;
024 import org.apache.commons.jxpath.ri.model.NodePointer;
025 import org.w3c.dom.Attr;
026 import org.w3c.dom.Element;
027 import org.w3c.dom.NamedNodeMap;
028 import org.w3c.dom.Node;
029
030 /**
031 * An iterator of attributes of a DOM Node.
032 *
033 * @author Dmitri Plotnikov
034 * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
035 */
036 public class DOMAttributeIterator implements NodeIterator {
037 private NodePointer parent;
038 private QName name;
039 private List attributes;
040 private int position = 0;
041
042 /**
043 * Create a new DOMAttributeIterator.
044 * @param parent pointer
045 * @param name to test
046 */
047 public DOMAttributeIterator(NodePointer parent, QName name) {
048 this.parent = parent;
049 this.name = name;
050 attributes = new ArrayList();
051 Node node = (Node) parent.getNode();
052 if (node.getNodeType() == Node.ELEMENT_NODE) {
053 String lname = name.getName();
054 if (!lname.equals("*")) {
055 Attr attr = getAttribute((Element) node, name);
056 if (attr != null) {
057 attributes.add(attr);
058 }
059 }
060 else {
061 NamedNodeMap map = node.getAttributes();
062 int count = map.getLength();
063 for (int i = 0; i < count; i++) {
064 Attr attr = (Attr) map.item(i);
065 if (testAttr(attr)) {
066 attributes.add(attr);
067 }
068 }
069 }
070 }
071 }
072
073 /**
074 * Test an attribute.
075 * @param attr to test
076 * @return whether test succeeded
077 */
078 private boolean testAttr(Attr attr) {
079 String nodePrefix = DOMNodePointer.getPrefix(attr);
080 String nodeLocalName = DOMNodePointer.getLocalName(attr);
081
082 if (nodePrefix != null && nodePrefix.equals("xmlns")) {
083 return false;
084 }
085
086 if (nodePrefix == null && nodeLocalName.equals("xmlns")) {
087 return false;
088 }
089
090 String testLocalName = name.getName();
091 if (testLocalName.equals("*") || testLocalName.equals(nodeLocalName)) {
092 String testPrefix = name.getPrefix();
093
094 if (testPrefix == null || equalStrings(testPrefix, nodePrefix)) {
095 return true;
096 }
097 if (nodePrefix == null) {
098 return false;
099 }
100 return equalStrings(parent.getNamespaceURI(testPrefix), parent
101 .getNamespaceURI(nodePrefix));
102 }
103 return false;
104 }
105
106 /**
107 * Test whether two strings are == or .equals()
108 * @param s1 first string
109 * @param s2 second string
110 * @return boolean
111 */
112 private static boolean equalStrings(String s1, String s2) {
113 return s1 == s2 || s1 != null && s1.equals(s2);
114 }
115
116 /**
117 * Get the named attribute.
118 * @param element to search
119 * @param name to match
120 * @return Attr found
121 */
122 private Attr getAttribute(Element element, QName name) {
123 String testPrefix = name.getPrefix();
124 String testNS = null;
125
126 if (testPrefix != null) {
127 testNS = parent.getNamespaceResolver().getNamespaceURI(testPrefix);
128 }
129
130 if (testNS != null) {
131 Attr attr = element.getAttributeNodeNS(testNS, name.getName());
132 if (attr != null) {
133 return attr;
134 }
135
136 // This may mean that the parser does not support NS for
137 // attributes, example - the version of Crimson bundled
138 // with JDK 1.4.0
139 NamedNodeMap nnm = element.getAttributes();
140 for (int i = 0; i < nnm.getLength(); i++) {
141 attr = (Attr) nnm.item(i);
142 if (testAttr(attr)) {
143 return attr;
144 }
145 }
146 return null;
147 }
148 return element.getAttributeNode(name.getName());
149 }
150
151 public NodePointer getNodePointer() {
152 if (position == 0) {
153 if (!setPosition(1)) {
154 return null;
155 }
156 position = 0;
157 }
158 int index = position - 1;
159 if (index < 0) {
160 index = 0;
161 }
162 return new DOMAttributePointer(parent, (Attr) attributes.get(index));
163 }
164
165 public int getPosition() {
166 return position;
167 }
168
169 public boolean setPosition(int position) {
170 this.position = position;
171 return position >= 1 && position <= attributes.size();
172 }
173 }