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1   /*
2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/expr/DefaultFilterExpr.java,v 1.16 2005/09/06 13:41:00 elharo Exp $
3    * $Revision: 1.16 $
4    * $Date: 2005/09/06 13:41:00 $
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: DefaultFilterExpr.java,v 1.16 2005/09/06 13:41:00 elharo Exp $
60   */
61  
62  
63  
64  package org.jaxen.expr;
65  
66  import java.util.ArrayList;
67  import java.util.List;
68  import org.jaxen.Context;
69  import org.jaxen.JaxenException;
70  
71  /***
72   * @deprecated this class will become non-public in the future;
73   *     use the interface instead
74   */
75  public class DefaultFilterExpr extends DefaultExpr implements FilterExpr, Predicated
76  {
77      private Expr expr;
78      private PredicateSet predicates;
79  
80      public DefaultFilterExpr(PredicateSet predicateSet)
81      {
82          this.predicates = predicateSet;
83      }
84  
85      public DefaultFilterExpr(Expr expr, PredicateSet predicateSet)
86      {
87          this.expr       = expr;
88          this.predicates = predicateSet;
89      }
90  
91      public void addPredicate(Predicate predicate)
92      {
93          this.predicates.addPredicate( predicate );
94      }
95  
96      public List getPredicates()
97      {
98          return this.predicates.getPredicates();
99      }
100 
101     public PredicateSet getPredicateSet()
102     {
103         return this.predicates;
104     }
105 
106     public Expr getExpr()
107     {
108         return this.expr;
109     }
110 
111     public String toString()
112     {
113         return "[(DefaultFilterExpr): expr: " + expr + " predicates: " + predicates + " ]";
114     }
115 
116     public String getText()
117     {
118         String text = "";
119         if ( this.expr != null )
120         {
121             text = this.expr.getText();
122         }
123         text += predicates.getText();
124         return text;
125     }
126 
127     public Expr simplify()
128     {
129         this.predicates.simplify();
130 
131         if ( this.expr != null ) 
132         {
133             this.expr = this.expr.simplify();
134         }
135 
136         if ( this.predicates.getPredicates().size() == 0 )
137         {
138             return getExpr();
139         }
140 
141         return this;
142     }
143 
144     /*** Returns true if the current filter matches at least one of the context nodes
145      */
146     public boolean asBoolean(Context context) throws JaxenException 
147     {
148         Object results = null;
149         if ( expr != null ) 
150         {
151             results = expr.evaluate( context );
152         }
153         else
154         {
155             List nodeSet = context.getNodeSet();
156             ArrayList list = new ArrayList(nodeSet.size());
157             list.addAll( nodeSet );
158             results = list;
159         }
160         
161         if ( results instanceof Boolean ) 
162         {
163             Boolean b = (Boolean) results;
164             return b.booleanValue();
165         }
166         if ( results instanceof List )
167         {
168             return getPredicateSet().evaluateAsBoolean( 
169                 (List) results, context.getContextSupport() 
170             );
171         }
172         
173         return false;
174     }
175     
176     public Object evaluate(Context context) throws JaxenException
177     {
178         Object results = getExpr().evaluate( context );
179         
180         if ( results instanceof List )
181         {
182             List newresults = getPredicateSet().evaluatePredicates( (List) results,
183                                     context.getContextSupport() );
184         results = newresults;
185         }
186 
187         return results;
188     }
189     public void accept(Visitor visitor)
190     {
191         visitor.visit(this);
192     }
193 }