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Java > Open Source Codes > org > jaxen > expr > DefaultLocationPath


1 /*
2  * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultLocationPath.java,v 1.26 2005/05/16 10:46:43 elharo Exp $
3  * $Revision: 1.26 $
4  * $Date: 2005/05/16 10:46:43 $
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 1.26 2005/05/16 10:46:43 elharo Exp $
60  */
61 package org.jaxen.expr;
62
63 import java.util.ArrayList JavaDoc;
64 import java.util.Collections JavaDoc;
65 import java.util.Iterator JavaDoc;
66 import java.util.LinkedList JavaDoc;
67 import java.util.List JavaDoc;
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 JavaDoc steps;
76     
77     /**
78      * Create a new empty location path.
79      */
80     DefaultLocationPath()
81     {
82         this.steps = new LinkedList JavaDoc();
83     }
84
85     public void addStep(Step step)
86     {
87         getSteps().add(step);
88     }
89
90     public List JavaDoc getSteps()
91     {
92         return this.steps;
93     }
94
95     public Expr simplify()
96     {
97         Iterator JavaDoc 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 JavaDoc getText()
108     {
109         StringBuffer JavaDoc buf = new StringBuffer JavaDoc();
110         Iterator JavaDoc 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 JavaDoc toString()
123     {
124         StringBuffer JavaDoc buf = new StringBuffer JavaDoc();
125         Iterator JavaDoc 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 JavaDoc evaluate(Context context) throws JaxenException
143     {
144         List JavaDoc nodeSet = context.getNodeSet();
145         List JavaDoc contextNodeSet = new ArrayList JavaDoc(nodeSet.size());
146         contextNodeSet.addAll(nodeSet);
147         ContextSupport support = context.getContextSupport();
148         Context stepContext = new Context(support);
149         Iterator JavaDoc 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
179
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