1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultStep.java,v 1.10 2005/03/28 22:01:55 elharo Exp $
3 * $Revision: 1.10 $
4 * $Date: 2005/03/28 22:01:55 $
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: DefaultStep.java,v 1.10 2005/03/28 22:01:55 elharo Exp $
60 */
61 package org.jaxen.expr;
62
63 import java.util.ArrayList;
64 import java.util.Iterator;
65 import java.util.List;
66 import java.util.Map;
67
68 import org.jaxen.Context;
69 import org.jaxen.ContextSupport;
70 import org.jaxen.JaxenException;
71 import org.jaxen.UnsupportedAxisException;
72 import org.jaxen.expr.iter.IterableAxis;
73 import org.jaxen.saxpath.Axis;
74 import org.jaxen.util.IdentityHashMap;
75
76 public abstract class DefaultStep implements Step
77 {
78 private IterableAxis axis;
79 private PredicateSet predicates;
80
81 private final static Object PRESENT = new Object();
82
83 public DefaultStep(IterableAxis axis, PredicateSet predicates)
84 {
85 this.axis = axis;
86 this.predicates = predicates;
87 }
88
89 public void addPredicate(Predicate predicate)
90 {
91 this.predicates.addPredicate(predicate);
92 }
93
94 public List getPredicates()
95 {
96 return this.predicates.getPredicates();
97 }
98
99 public PredicateSet getPredicateSet()
100 {
101 return this.predicates;
102 }
103
104 public int getAxis()
105 {
106 return this.axis.value();
107 }
108
109 public IterableAxis getIterableAxis()
110 {
111 return this.axis;
112 }
113
114 public String getAxisName()
115 {
116 return Axis.lookup(getAxis());
117 }
118
119 public String getText()
120 {
121 return this.predicates.getText();
122 }
123
124 public String toString()
125 {
126 return getIterableAxis() + " " + super.toString();
127 }
128
129 public void simplify()
130 {
131 this.predicates.simplify();
132 }
133
134 public Iterator axisIterator(Object contextNode, ContextSupport support)
135 throws UnsupportedAxisException
136 {
137 return getIterableAxis().iterator(contextNode, support);
138 }
139
140 public List evaluate(Context context) throws JaxenException
141 {
142 List contextNodeSet = context.getNodeSet();
143 Map unique = new IdentityHashMap();
144 int contextSize = contextNodeSet.size();
145
146 List interimSet = new ArrayList();
147 List newNodeSet = new ArrayList();
148 ContextSupport support = context.getContextSupport();
149
150 for ( int i = 0 ; i < contextSize ; ++i )
151 {
152 Object eachContextNode = contextNodeSet.get( i );
153
154 Iterator axisNodeIter = axisIterator( eachContextNode, support );
155 if ( axisNodeIter == null )
156 {
157 continue;
158 }
159
160 while ( axisNodeIter.hasNext() )
161 {
162 Object eachAxisNode = axisNodeIter.next();
163
164 if ( matches( eachAxisNode, support ) )
165 {
166 if ( ! unique.containsKey( eachAxisNode ) )
167 {
168 unique.put( eachAxisNode, PRESENT );
169 interimSet.add( eachAxisNode );
170 }
171 }
172 }
173 newNodeSet.addAll(getPredicateSet().evaluatePredicates(
174 interimSet, support ));
175 interimSet.clear();
176 }
177 return newNodeSet;
178 }
179
180 }