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 < 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 ASTLTNode extends SimpleNode
41 {
42 /**
43 * @param id
44 */
45 public ASTLTNode(int id)
46 {
47 super(id);
48 }
49
50 /**
51 * @param p
52 * @param id
53 */
54 public ASTLTNode(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 valid Number. "
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 }