1 /*
2 * $Header$
3 * $Revision$
4 * $Date$
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 * $Id$
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 public abstract class DefaultStep implements Step
61 {
62 private IterableAxis axis;
63 private PredicateSet predicates;
64
65 DefaultStep(IterableAxis axis, PredicateSet predicates)
66 {
67 this.axis = axis;
68 this.predicates = predicates;
69 }
70
71 public void addPredicate(Predicate predicate)
72 {
73 this.predicates.addPredicate(predicate);
74 }
75
76 public List getPredicates()
77 {
78 return this.predicates.getPredicates();
79 }
80
81 public PredicateSet getPredicateSet()
82 {
83 return this.predicates;
84 }
85
86 public int getAxis()
87 {
88 return this.axis.value();
89 }
90
91 public IterableAxis getIterableAxis()
92 {
93 return this.axis;
94 }
95
96 public String getAxisName()
97 {
98 return Axis.lookup(getAxis());
99 }
100
101 public String getText()
102 {
103 return this.predicates.getText();
104 }
105
106 @Override
107 public String toString()
108 {
109 return getIterableAxis() + " " + super.toString();
110 }
111
112 public void simplify()
113 {
114 this.predicates.simplify();
115 }
116
117 public Iterator axisIterator(Object contextNode, ContextSupport support)
118 throws UnsupportedAxisException
119 {
120 return getIterableAxis().iterator(contextNode, support);
121 }
122
123 public List evaluate(final Context context) throws JaxenException
124 {
125 final List contextNodeSet = context.getNodeSet();
126 final IdentitySet unique = new IdentitySet();
127 final int contextSize = contextNodeSet.size();
128
129 // ???? try linked lists instead?
130 // ???? initial size for these?
131 final ArrayList<Object> interimSet = new ArrayList<Object>();
132 final ArrayList<Object> newNodeSet = new ArrayList<Object>();
133 final ContextSupport support = context.getContextSupport();
134
135 // ???? use iterator instead
136 for ( int i = 0 ; i < contextSize ; ++i )
137 {
138 Object eachContextNode = contextNodeSet.get( i );
139
140
141 /* See jaxen-106. Might be able to optimize this by doing
142 * specific matching for individual axes. For instance on namespace axis
143 * we should only get namespace nodes and on attribute axes we only get
144 * attribute nodes. Self and parent axes have single members.
145 * Children, descendant, ancestor, and sibling axes never
146 * see any attributes or namespaces
147 */
148 Iterator<?> axisNodeIter = axis.iterator(eachContextNode, support);
149 while ( axisNodeIter.hasNext() )
150 {
151 Object eachAxisNode = axisNodeIter.next();
152 if ( ! unique.contains( eachAxisNode ) )
153 {
154 if ( matches( eachAxisNode, support ) )
155 {
156 unique.add( eachAxisNode );
157 interimSet.add( eachAxisNode );
158 }
159 }
160 }
161 newNodeSet.addAll(getPredicateSet().evaluatePredicates(
162 interimSet, support ));
163 interimSet.clear();
164 }
165 return newNodeSet;
166 }
167
168 }