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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.parser.Parser;
25  import org.apache.velocity.util.TemplateNumber;
26  
27  /**
28   * Handles arg1 &gt; arg2<br><br>
29   *
30   * Only subclasses of Number can be compared.<br><br>
31   *
32   * Please look at the Parser.jjt file which is
33   * what controls the generation of this class.
34   *
35   * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
36   * @author <a href="mailto:pero@antaramusic.de">Peter Romianowski</a>
37   */
38  
39  public class ASTGTNode extends SimpleNode
40  {
41      /**
42       * @param id
43       */
44      public ASTGTNode(int id)
45      {
46          super(id);
47      }
48  
49      /**
50       * @param p
51       * @param id
52       */
53      public ASTGTNode(Parser p, int id)
54      {
55          super(p, id);
56      }
57  
58  
59      /**
60       * @see org.apache.velocity.runtime.parser.node.SimpleNode#jjtAccept(org.apache.velocity.runtime.parser.node.ParserVisitor, java.lang.Object)
61       */
62      public Object jjtAccept(ParserVisitor visitor, Object data)
63      {
64          return visitor.visit(this, data);
65      }
66  
67      /**
68       * @see org.apache.velocity.runtime.parser.node.SimpleNode#evaluate(org.apache.velocity.context.InternalContextAdapter)
69       */
70      public boolean evaluate(InternalContextAdapter context)
71          throws MethodInvocationException
72      {
73          /*
74           *  get the two args
75           */
76  
77          Object left = jjtGetChild(0).value( context );
78          Object right = jjtGetChild(1).value( context );
79  
80          /*
81           *  if either is null, lets log and bail
82           */
83  
84          if (left == null || right == null)
85          {
86              log.error((left == null ? "Left" : "Right")
87                             + " side ("
88                             + jjtGetChild( (left == null? 0 : 1) ).literal()
89                             + ") of '>' operation has null value."
90                             + " Operation not possible. "
91                             + context.getCurrentTemplateName() + " [line "
92                             + getLine()
93                             + ", column " + getColumn() + "]");
94              return false;
95          }
96  
97          /*
98           *  convert to Number if applicable
99           */
100         if (left instanceof TemplateNumber)
101         {
102            left = ( (TemplateNumber) left).getAsNumber();
103         }
104         if (right instanceof TemplateNumber)
105         {
106            right = ( (TemplateNumber) right).getAsNumber();
107         }
108 
109         /*
110          *  Only compare Numbers
111          */
112 
113         if ( !( left instanceof Number )  || !( right instanceof Number ))
114         {
115             log.error((!(left instanceof Number) ? "Left" : "Right")
116                            + " side of '>=' operation is not a Numbere. "
117                            +  context.getCurrentTemplateName() + " [line " + getLine()
118                            + ", column " + getColumn() + "]");
119 
120             return false;
121         }
122 
123         return MathUtils.compare ( (Number)left,(Number)right) == 1;
124 
125     }
126 
127     /**
128      * @see org.apache.velocity.runtime.parser.node.SimpleNode#value(org.apache.velocity.context.InternalContextAdapter)
129      */
130     public Object value(InternalContextAdapter context)
131         throws MethodInvocationException
132     {
133         boolean val = evaluate(context);
134 
135         return val ? Boolean.TRUE : Boolean.FALSE;
136     }
137 
138 }