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1   /*
2    * $Header$
3    * $Revision: 1261 $
4    * $Date: 2006-11-30 10:49:27 -0800 (Thu, 30 Nov 2006) $
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: DefaultOrExpr.java 1261 2006-11-30 18:49:27Z elharo $
46   */
47  
48  
49  
50  package org.jaxen.expr;
51  
52  import org.jaxen.Context;
53  import org.jaxen.JaxenException;
54  import org.jaxen.Navigator;
55  import org.jaxen.function.BooleanFunction;
56  
57  class DefaultOrExpr extends DefaultLogicalExpr 
58  {
59      /**
60       * 
61       */
62      private static final long serialVersionUID = 4894552680753026730L;
63  
64      DefaultOrExpr(Expr lhs,
65                           Expr rhs)
66      {
67          super( lhs,
68                 rhs );
69      }
70  
71      public String getOperator()
72      {
73          return "or";
74      }
75  
76      public String toString()
77      {
78          return "[(DefaultOrExpr): " + getLHS() + ", " + getRHS() + "]";
79      }
80  
81      public Object evaluate(Context context) throws JaxenException
82      {
83          Navigator nav = context.getNavigator();
84          Boolean lhsValue = BooleanFunction.evaluate( getLHS().evaluate( context ), nav );
85  
86          if ( lhsValue.booleanValue() )
87          {
88              return Boolean.TRUE;
89          }
90  
91          // Short circuits are required in XPath. "The right operand is not 
92          // evaluated if the left operand evaluates to true."
93          Boolean rhsValue = BooleanFunction.evaluate( getRHS().evaluate( context ), nav );
94  
95          if ( rhsValue.booleanValue() )
96          {
97              return Boolean.TRUE;
98          }
99  
100         return Boolean.FALSE;
101     }
102     
103 }