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1   package org.apache.velocity.runtime.parser.node;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.    
20   */
21  
22  import org.apache.velocity.context.InternalContextAdapter;
23  import org.apache.velocity.exception.MethodInvocationException;
24  import org.apache.velocity.runtime.log.Log;
25  import org.apache.velocity.runtime.parser.Parser;
26  import org.apache.velocity.util.TemplateNumber;
27  
28  /**
29   * Handles arg1 &gt; arg2<br><br>
30   *
31   * Only subclasses of Number can be compared.<br><br>
32   *
33   * Please look at the Parser.jjt file which is
34   * what controls the generation of this class.
35   *
36   * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
37   * @author <a href="mailto:pero@antaramusic.de">Peter Romianowski</a>
38   */
39  
40  public class ASTGTNode extends SimpleNode
41  {
42      /**
43       * @param id
44       */
45      public ASTGTNode(int id)
46      {
47          super(id);
48      }
49  
50      /**
51       * @param p
52       * @param id
53       */
54      public ASTGTNode(Parser p, int id)
55      {
56          super(p, id);
57      }
58  
59  
60      /**
61       * @see org.apache.velocity.runtime.parser.node.SimpleNode#jjtAccept(org.apache.velocity.runtime.parser.node.ParserVisitor, java.lang.Object)
62       */
63      public Object jjtAccept(ParserVisitor visitor, Object data)
64      {
65          return visitor.visit(this, data);
66      }
67  
68      /**
69       * @see org.apache.velocity.runtime.parser.node.SimpleNode#evaluate(org.apache.velocity.context.InternalContextAdapter)
70       */
71      public boolean evaluate(InternalContextAdapter context)
72          throws MethodInvocationException
73      {
74          /*
75           *  get the two args
76           */
77  
78          Object left = jjtGetChild(0).value( context );
79          Object right = jjtGetChild(1).value( context );
80  
81          /*
82           *  if either is null, lets log and bail
83           */
84  
85          if (left == null || right == null)
86          {
87              log.error((left == null ? "Left" : "Right")
88                             + " side ("
89                             + jjtGetChild( (left == null? 0 : 1) ).literal()
90                             + ") of '>' operation has null value."
91                             + " Operation not possible. "
92                             + Log.formatFileString(this));
93              return false;
94          }
95  
96          /*
97           *  convert to Number if applicable
98           */
99          if (left instanceof TemplateNumber)
100         {
101            left = ( (TemplateNumber) left).getAsNumber();
102         }
103         if (right instanceof TemplateNumber)
104         {
105            right = ( (TemplateNumber) right).getAsNumber();
106         }
107 
108         /*
109          *  Only compare Numbers
110          */
111 
112         if ( !( left instanceof Number )  || !( right instanceof Number ))
113         {
114             log.error((!(left instanceof Number) ? "Left" : "Right")
115                            + " side of '>=' operation is not a Numbere. "
116                            + Log.formatFileString(this));
117 
118             return false;
119         }
120 
121         return MathUtils.compare ( (Number)left,(Number)right) == 1;
122 
123     }
124 
125     /**
126      * @see org.apache.velocity.runtime.parser.node.SimpleNode#value(org.apache.velocity.context.InternalContextAdapter)
127      */
128     public Object value(InternalContextAdapter context)
129         throws MethodInvocationException
130     {
131         boolean val = evaluate(context);
132 
133         return val ? Boolean.TRUE : Boolean.FALSE;
134     }
135 
136 }