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 < 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 ASTLTNode extends SimpleNode
42 {
43 /**
44 * @param id
45 */
46 public ASTLTNode(int id)
47 {
48 super(id);
49 }
50
51 /**
52 * @param p
53 * @param id
54 */
55 public ASTLTNode(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
115 if ( !( left instanceof Number ) || !( right instanceof Number ))
116 {
117 log.error((!(left instanceof Number) ? "Left" : "Right")
118 + " side of '>=' operation is not a valid Number. "
119 + context.getCurrentTemplateName() + " [line " + getLine()
120 + ", column " + getColumn() + "]");
121
122 return false;
123 }
124
125 return MathUtils.compare ( (Number)left,(Number)right) == -1;
126
127 }
128
129 /**
130 * @see org.apache.velocity.runtime.parser.node.SimpleNode#value(org.apache.velocity.context.InternalContextAdapter)
131 */
132 public Object value(InternalContextAdapter context)
133 throws MethodInvocationException
134 {
135 boolean val = evaluate(context);
136
137 return val ? Boolean.TRUE : Boolean.FALSE;
138 }
139
140 }