1 /*
2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultStep.java,v 1.21 2006/02/05 21:47:40 elharo Exp $
3 * $Revision: 1.21 $
4 * $Date: 2006/02/05 21:47:40 $
5 *
6 * ====================================================================
7 *
8 * Copyright 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 are
13 * met:
14 *
15 * * Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 *
18 * * Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * * Neither the name of the Jaxen Project nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
30 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * ====================================================================
39 * This software consists of voluntary contributions made by many
40 * individuals on behalf of the Jaxen Project and was originally
41 * created by bob mcwhirter <bob@werken.com> and
42 * James Strachan <jstrachan@apache.org>. For more information on the
43 * Jaxen Project, please see <http://www.jaxen.org/>.
44 *
45 * $Id: DefaultStep.java,v 1.21 2006/02/05 21:47:40 elharo Exp $
46 */
47 package org.jaxen.expr;
48
49 import java.util.ArrayList;
50 import java.util.Iterator;
51 import java.util.List;
52
53 import org.jaxen.Context;
54 import org.jaxen.ContextSupport;
55 import org.jaxen.JaxenException;
56 import org.jaxen.UnsupportedAxisException;
57 import org.jaxen.expr.iter.IterableAxis;
58 import org.jaxen.saxpath.Axis;
59
60 /***
61 * @deprecated this class will become non-public in the future;
62 * use the interface instead
63 */
64 public abstract class DefaultStep implements Step
65 {
66 private IterableAxis axis;
67 private PredicateSet predicates;
68
69 public DefaultStep(IterableAxis axis, PredicateSet predicates)
70 {
71 this.axis = axis;
72 this.predicates = predicates;
73 }
74
75 public void addPredicate(Predicate predicate)
76 {
77 this.predicates.addPredicate(predicate);
78 }
79
80 public List getPredicates()
81 {
82 return this.predicates.getPredicates();
83 }
84
85 public PredicateSet getPredicateSet()
86 {
87 return this.predicates;
88 }
89
90 public int getAxis()
91 {
92 return this.axis.value();
93 }
94
95 public IterableAxis getIterableAxis()
96 {
97 return this.axis;
98 }
99
100 public String getAxisName()
101 {
102 return Axis.lookup(getAxis());
103 }
104
105 public String getText()
106 {
107 return this.predicates.getText();
108 }
109
110 public String toString()
111 {
112 return getIterableAxis() + " " + super.toString();
113 }
114
115 public void simplify()
116 {
117 this.predicates.simplify();
118 }
119
120 public Iterator axisIterator(Object contextNode, ContextSupport support)
121 throws UnsupportedAxisException
122 {
123 return getIterableAxis().iterator(contextNode, support);
124 }
125
126 public List evaluate(final Context context) throws JaxenException
127 {
128 final List contextNodeSet = context.getNodeSet();
129 final IdentitySet unique = new IdentitySet();
130 final int contextSize = contextNodeSet.size();
131
132 // ???? try linked lists instead?
133 // ???? initial size for these?
134 final ArrayList interimSet = new ArrayList();
135 final ArrayList newNodeSet = new ArrayList();
136 final ContextSupport support = context.getContextSupport();
137
138 // ???? use iterator instead
139 for ( int i = 0 ; i < contextSize ; ++i )
140 {
141 Object eachContextNode = contextNodeSet.get( i );
142
143
144 /* See jaxen-106. Might be able to optimize this by doing
145 * specific matching for individual axes. For instance on namespace axis
146 * we should only get namespace nodes and on attribute axes we only get
147 * attribute nodes. Self and parent axes have single members.
148 * Children, descendant, ancestor, and sibling axes never
149 * see any attributes or namespaces
150 */
151 Iterator axisNodeIter = axis.iterator(eachContextNode, support);
152 while ( axisNodeIter.hasNext() )
153 {
154 Object eachAxisNode = axisNodeIter.next();
155 if ( ! unique.contains( eachAxisNode ) )
156 {
157 if ( matches( eachAxisNode, support ) )
158 {
159 unique.add( eachAxisNode );
160 interimSet.add( eachAxisNode );
161 }
162 }
163 }
164 newNodeSet.addAll(getPredicateSet().evaluatePredicates(
165 interimSet, support ));
166 interimSet.clear();
167 }
168 return newNodeSet;
169 }
170
171 }