001: /*
002: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
003: *
004: * This file is part of Resin(R) Open Source
005: *
006: * Each copy or derived work must preserve the copyright notice and this
007: * notice unmodified.
008: *
009: * Resin Open Source is free software; you can redistribute it and/or modify
010: * it under the terms of the GNU General Public License as published by
011: * the Free Software Foundation; either version 2 of the License, or
012: * (at your option) any later version.
013: *
014: * Resin Open Source is distributed in the hope that it will be useful,
015: * but WITHOUT ANY WARRANTY; without even the implied warranty of
016: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
017: * of NON-INFRINGEMENT. See the GNU General Public License for more
018: * details.
019: *
020: * You should have received a copy of the GNU General Public License
021: * along with Resin Open Source; if not, write to the
022: * Free SoftwareFoundation, Inc.
023: * 59 Temple Place, Suite 330
024: * Boston, MA 02111-1307 USA
025: *
026: * @author Scott Ferguson
027: */
028:
029: package com.caucho.xpath.pattern;
030:
031: import com.caucho.xpath.ExprEnvironment;
032: import com.caucho.xpath.XPathException;
033:
034: import org.w3c.dom.Node;
035:
036: /**
037: * Matches a named node, like para or @id.
038: */
039: public class NodePattern extends AbstractPattern {
040: private NodePattern _match;
041:
042: private String _tag;
043: private int _nodeType;
044:
045: /**
046: * Creates a new node-matching pattern.
047: */
048: public NodePattern(AbstractPattern parent, String tag, int nodeType) {
049: super (parent);
050:
051: _tag = tag.intern();
052: _nodeType = nodeType;
053: }
054:
055: /**
056: * All priorities are based on the node priority.
057: */
058: public double getPriority() {
059: if (_parent == null
060: || _parent instanceof FromChildren
061: && (_parent._parent instanceof FromAny || _parent._parent instanceof FromContext))
062: return 0;
063: else
064: return 0.5;
065: }
066:
067: /**
068: * Returns the pattern's matching node name.
069: */
070: public String getNodeName() {
071: return _tag;
072: }
073:
074: /**
075: * matches if the node type matches and the node name matches.
076: *
077: * @param node the node to test.
078: * @param env the variable environment
079: *
080: * @return true if the node matches
081: */
082: public boolean match(Node node, ExprEnvironment env)
083: throws XPathException {
084: if (node == null)
085: return false;
086:
087: if (node.getNodeType() != _nodeType)
088: return false;
089: else if (!node.getNodeName().equals(_tag))
090: return false;
091: else if (node.getNamespaceURI() != null)
092: return false;
093: else if (_parent != null && !_parent.match(node, env))
094: return false;
095:
096: return true;
097: }
098:
099: /**
100: * Copies the position (non-axis) portion of the pattern.
101: */
102: public AbstractPattern copyPosition() {
103: if (_match == null) {
104: AbstractPattern parent = null;
105: if (_parent != null)
106: parent = _parent.copyPosition();
107: _match = new NodePattern(parent, _tag, _nodeType);
108: }
109:
110: return _match;
111: }
112:
113: /**
114: * Returns true if the two patterns are equal.
115: */
116: public boolean equals(Object b) {
117: if (!(b instanceof NodePattern))
118: return false;
119:
120: NodePattern bPattern = (NodePattern) b;
121:
122: return (_nodeType == bPattern._nodeType
123: && _tag.equals(bPattern._tag) && (_parent == bPattern._parent || (_parent != null && _parent
124: .equals(bPattern._parent))));
125: }
126:
127: /**
128: * Converts the pattern back to its
129: */
130: public String toString() {
131: String prefix;
132:
133: if (_parent == null || _parent instanceof FromAny)
134: prefix = "";
135: else if (_parent instanceof FromChildren)
136: prefix = _parent.getPrefix();
137: else
138: prefix = _parent.toString();
139:
140: switch (_nodeType) {
141: case Node.PROCESSING_INSTRUCTION_NODE:
142: return prefix + "pi('" + _tag + "')";
143:
144: case Node.ATTRIBUTE_NODE:
145: return prefix + _tag;
146:
147: case Node.ELEMENT_NODE:
148: return prefix + _tag;
149:
150: default:
151: return super.toString();
152: }
153: }
154: }
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