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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.runtime.parser.Parser;
24  import org.apache.velocity.runtime.parser.ParserVisitor;
25  
26  import org.apache.velocity.exception.MethodInvocationException;
27  import org.apache.velocity.util.TemplateNumber;
28  
29  /**
30   * Handles arg1 &lt;= arg2<br><br>
31   *
32   * Only subclasses of Number can be compared.<br><br>
33   *
34   * Please look at the Parser.jjt file which is
35   * what controls the generation of this class.
36   *
37   * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
38   * @author <a href="mailto:pero@antaramusic.de">Peter Romianowski</a>
39   */
40  
41  public class ASTLENode extends SimpleNode
42  {
43      /**
44       * @param id
45       */
46      public ASTLENode(int id)
47      {
48          super(id);
49      }
50  
51      /**
52       * @param p
53       * @param id
54       */
55      public ASTLENode(Parser p, int id)
56      {
57          super(p, id);
58      }
59  
60  
61      /**
62       * @see org.apache.velocity.runtime.parser.node.SimpleNode#jjtAccept(org.apache.velocity.runtime.parser.ParserVisitor, java.lang.Object)
63       */
64      public Object jjtAccept(ParserVisitor visitor, Object data)
65      {
66          return visitor.visit(this, data);
67      }
68  
69      /**
70       * @see org.apache.velocity.runtime.parser.node.SimpleNode#evaluate(org.apache.velocity.context.InternalContextAdapter)
71       */
72      public boolean evaluate( InternalContextAdapter context)
73        throws MethodInvocationException
74      {
75          /*
76           *  get the two args
77           */
78  
79          Object left = jjtGetChild(0).value( context );
80          Object right = jjtGetChild(1).value( context );
81  
82          /*
83           *  if either is null, lets log and bail
84           */
85  
86          if (left == null || right == null)
87          {
88              log.error((left == null ? "Left" : "Right")
89                             + " side ("
90                             + jjtGetChild( (left == null? 0 : 1) ).literal()
91                             + ") of '<=' operation has null value."
92                             + " Operation not possible. "
93                             + context.getCurrentTemplateName() + " [line "
94                             + getLine()
95                             + ", column " + getColumn() + "]");
96              return false;
97          }
98  
99          /*
100          *  convert to Number if applicable
101          */
102         if (left instanceof TemplateNumber)
103         {
104            left = ( (TemplateNumber) left).getAsNumber();
105         }
106         if (right instanceof TemplateNumber)
107         {
108            right = ( (TemplateNumber) right).getAsNumber();
109         }
110 
111         /*
112          *  Only compare Numbers
113          */
114         if ( !( left instanceof Number )  || !( right instanceof Number ))
115         {
116             log.error((!(left instanceof Number) ? "Left" : "Right")
117                            + " side of '>=' operation is not a Number. "
118                            +  context.getCurrentTemplateName() + " [line " + getLine()
119                            + ", column " + getColumn() + "]");
120 
121             return false;
122         }
123 
124         return MathUtils.compare ( (Number)left,(Number)right) <= 0;
125 
126     }
127 
128     /**
129      * @see org.apache.velocity.runtime.parser.node.SimpleNode#value(org.apache.velocity.context.InternalContextAdapter)
130      */
131     public Object value(InternalContextAdapter context)
132         throws MethodInvocationException
133     {
134         boolean val = evaluate(context);
135 
136         return val ? Boolean.TRUE : Boolean.FALSE;
137     }
138 
139 }