1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultLocationPath.java,v 1.27 2005/06/28 13:44:44 elharo Exp $
3 * $Revision: 1.27 $
4 * $Date: 2005/06/28 13:44:44 $
5 *
6 * ====================================================================
7 *
8 * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer.
17 *
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions, and the disclaimer that follows
20 * these conditions in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * 3. The name "Jaxen" must not be used to endorse or promote products
24 * derived from this software without prior written permission. For
25 * written permission, please contact license@jaxen.org.
26 *
27 * 4. Products derived from this software may not be called "Jaxen", nor
28 * may "Jaxen" appear in their name, without prior written permission
29 * from the Jaxen Project Management (pm@jaxen.org).
30 *
31 * In addition, we request (but do not require) that you include in the
32 * end-user documentation provided with the redistribution and/or in the
33 * software itself an acknowledgement equivalent to the following:
34 * "This product includes software developed by the
35 * Jaxen Project <http://www.jaxen.org/>."
36 * Alternatively, the acknowledgment may be graphical using the logos
37 * available at http://www.jaxen.org/
38 *
39 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
40 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
41 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42 * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
43 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
45 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
46 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
47 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
48 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
49 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * ====================================================================
53 * This software consists of voluntary contributions made by many
54 * individuals on behalf of the Jaxen Project and was originally
55 * created by bob mcwhirter <bob@werken.com> and
56 * James Strachan <jstrachan@apache.org>. For more information on the
57 * Jaxen Project, please see <http://www.jaxen.org/>.
58 *
59 * $Id: DefaultLocationPath.java,v 1.27 2005/06/28 13:44:44 elharo Exp $
60 */
61 package org.jaxen.expr;
62
63 import java.util.ArrayList;
64 import java.util.Collections;
65 import java.util.Iterator;
66 import java.util.LinkedList;
67 import java.util.List;
68
69 import org.jaxen.Context;
70 import org.jaxen.ContextSupport;
71 import org.jaxen.JaxenException;
72
73 abstract class DefaultLocationPath extends DefaultExpr implements LocationPath
74 {
75 private List steps;
76
77 /***
78 * Create a new empty location path.
79 */
80 DefaultLocationPath()
81 {
82 this.steps = new LinkedList();
83 }
84
85 public void addStep(Step step)
86 {
87 getSteps().add(step);
88 }
89
90 public List getSteps()
91 {
92 return this.steps;
93 }
94
95 public Expr simplify()
96 {
97 Iterator stepIter = getSteps().iterator();
98 Step eachStep = null;
99 while (stepIter.hasNext())
100 {
101 eachStep = (Step) stepIter.next();
102 eachStep.simplify();
103 }
104 return this;
105 }
106
107 public String getText()
108 {
109 StringBuffer buf = new StringBuffer();
110 Iterator stepIter = getSteps().iterator();
111 while (stepIter.hasNext())
112 {
113 buf.append(((Step) stepIter.next()).getText());
114 if (stepIter.hasNext())
115 {
116 buf.append("/");
117 }
118 }
119 return buf.toString();
120 }
121
122 public String toString()
123 {
124 StringBuffer buf = new StringBuffer();
125 Iterator stepIter = getSteps().iterator();
126 while (stepIter.hasNext())
127 {
128 buf.append(stepIter.next().toString());
129 if (stepIter.hasNext())
130 {
131 buf.append("/");
132 }
133 }
134 return buf.toString();
135 }
136
137 public boolean isAbsolute()
138 {
139 return false;
140 }
141
142 public Object evaluate(Context context) throws JaxenException
143 {
144 List nodeSet = context.getNodeSet();
145 List contextNodeSet = new ArrayList(nodeSet.size());
146 contextNodeSet.addAll(nodeSet);
147 ContextSupport support = context.getContextSupport();
148 Context stepContext = new Context(support);
149 Iterator stepIter = getSteps().iterator();
150 while ( stepIter.hasNext() )
151 {
152 Step eachStep = (Step) stepIter.next();
153 stepContext.setNodeSet(contextNodeSet);
154 contextNodeSet = eachStep.evaluate(stepContext);
155 // now we need to reverse the list if this is a reverse axis
156 if (isReverseAxis(eachStep)) {
157 Collections.reverse(contextNodeSet);
158 }
159 }
160
161 if (getSteps().size() > 1) {
162 Collections.sort(contextNodeSet, new NodeComparator(support.getNavigator()));
163 }
164
165 return contextNodeSet;
166 }
167
168 private boolean isReverseAxis(Step step) {
169
170 int axis = step.getAxis();
171 return axis == org.jaxen.saxpath.Axis.PRECEDING
172 || axis == org.jaxen.saxpath.Axis.PRECEDING_SIBLING
173 || axis == org.jaxen.saxpath.Axis.ANCESTOR
174 || axis == org.jaxen.saxpath.Axis.ANCESTOR_OR_SELF;
175 }
176
177 }
178