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
018package org.apache.commons.jxpath.ri.model.dom;
019
020import java.util.ArrayList;
021import java.util.List;
022import java.util.Objects;
023
024import org.apache.commons.jxpath.ri.QName;
025import org.apache.commons.jxpath.ri.model.NodeIterator;
026import org.apache.commons.jxpath.ri.model.NodePointer;
027import org.w3c.dom.Attr;
028import org.w3c.dom.Element;
029import org.w3c.dom.NamedNodeMap;
030import org.w3c.dom.Node;
031
032/**
033 * An iterator of attributes of a DOM Node.
034 */
035public class DOMAttributeIterator implements NodeIterator {
036
037    private final NodePointer parent;
038    private final QName qName;
039    private final List<Attr> attributes;
040    private int position;
041
042    /**
043     * Constructs a new DOMAttributeIterator.
044     *
045     * @param parent pointer
046     * @param qName   to test
047     */
048    public DOMAttributeIterator(final NodePointer parent, final QName qName) {
049        this.parent = parent;
050        this.qName = qName;
051        attributes = new ArrayList<>();
052        final Node node = (Node) parent.getNode();
053        if (node.getNodeType() == Node.ELEMENT_NODE) {
054            final String lname = qName.getName();
055            if (!lname.equals("*")) {
056                final Attr attr = getAttribute((Element) node, qName);
057                if (attr != null) {
058                    attributes.add(attr);
059                }
060            } else {
061                final NamedNodeMap map = node.getAttributes();
062                final int count = map.getLength();
063                for (int i = 0; i < count; i++) {
064                    final Attr attr = (Attr) map.item(i);
065                    if (testAttr(attr)) {
066                        attributes.add(attr);
067                    }
068                }
069            }
070        }
071    }
072
073    /**
074     * Gets the named attribute.
075     *
076     * @param element to search
077     * @param qName    to match
078     * @return Attr found
079     */
080    private Attr getAttribute(final Element element, final QName qName) {
081        final String testPrefix = qName.getPrefix();
082        String testNS = null;
083        if (testPrefix != null) {
084            testNS = parent.getNamespaceResolver().getNamespaceURI(testPrefix);
085        }
086        if (testNS != null) {
087            Attr attr = element.getAttributeNodeNS(testNS, qName.getName());
088            if (attr != null) {
089                return attr;
090            }
091            // This may mean that the parser does not support NS for
092            // attributes, example - the version of Crimson bundled
093            // with JDK 1.4.0
094            final NamedNodeMap nnm = element.getAttributes();
095            for (int i = 0; i < nnm.getLength(); i++) {
096                attr = (Attr) nnm.item(i);
097                if (testAttr(attr)) {
098                    return attr;
099                }
100            }
101            return null;
102        }
103        return element.getAttributeNode(qName.getName());
104    }
105
106    @Override
107    public NodePointer getNodePointer() {
108        if (position == 0) {
109            if (!setPosition(1)) {
110                return null;
111            }
112            position = 0;
113        }
114        int index = position - 1;
115        if (index < 0) {
116            index = 0;
117        }
118        return new DOMAttributePointer(parent, attributes.get(index));
119    }
120
121    @Override
122    public int getPosition() {
123        return position;
124    }
125
126    @Override
127    public boolean setPosition(final int position) {
128        this.position = position;
129        return position >= 1 && position <= attributes.size();
130    }
131
132    /**
133     * Test an attribute.
134     *
135     * @param attr to test
136     * @return whether test succeeded
137     */
138    private boolean testAttr(final Attr attr) {
139        final String nodePrefix = DOMNodePointer.getPrefix(attr);
140        final String nodeLocalName = DOMNodePointer.getLocalName(attr);
141        if (nodePrefix != null && nodePrefix.equals("xmlns")) {
142            return false;
143        }
144        if (nodePrefix == null && nodeLocalName.equals("xmlns")) {
145            return false;
146        }
147        final String testLocalName = qName.getName();
148        if (testLocalName.equals("*") || testLocalName.equals(nodeLocalName)) {
149            final String testPrefix = qName.getPrefix();
150            if (testPrefix == null || Objects.equals(testPrefix, nodePrefix)) {
151                return true;
152            }
153            if (nodePrefix == null) {
154                return false;
155            }
156            return Objects.equals(parent.getNamespaceURI(testPrefix), parent.getNamespaceURI(nodePrefix));
157        }
158        return false;
159    }
160}