KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > freemarker > core > ConditionalBlock


1 /*
2  * Copyright (c) 2003 The Visigoth Software Society. All rights
3  * reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  * notice, this list of conditions and the following disclaimer in
14  * the documentation and/or other materials provided with the
15  * distribution.
16  *
17  * 3. The end-user documentation included with the redistribution, if
18  * any, must include the following acknowledgement:
19  * "This product includes software developed by the
20  * Visigoth Software Society (http://www.visigoths.org/)."
21  * Alternately, this acknowledgement may appear in the software itself,
22  * if and wherever such third-party acknowledgements normally appear.
23  *
24  * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
25  * project contributors may be used to endorse or promote products derived
26  * from this software without prior written permission. For written
27  * permission, please contact visigoths@visigoths.org.
28  *
29  * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
30  * nor may "FreeMarker" or "Visigoth" appear in their names
31  * without prior written permission of the Visigoth Software Society.
32  *
33  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
34  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
36  * DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
37  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
38  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
39  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
40  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
41  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
42  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
43  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44  * SUCH DAMAGE.
45  * ====================================================================
46  *
47  * This software consists of voluntary contributions made by many
48  * individuals on behalf of the Visigoth Software Society. For more
49  * information on the Visigoth Software Society, please see
50  * http://www.visigoths.org/
51  */

52
53 package freemarker.core;
54
55 import java.io.IOException JavaDoc;
56 import freemarker.template.*;
57
58 /**
59  * An element that represents a conditionally executed block.
60  * @author <A HREF="mailto:jon@revusky.com">Jonathan Revusky</A>
61  */

62
63 final class ConditionalBlock extends TemplateElement {
64
65     final Expression condition;
66     private final boolean isFirst;
67     boolean isSimple;
68
69     ConditionalBlock(Expression condition, TemplateElement nestedBlock, boolean isFirst)
70     {
71         this.condition = condition;
72         this.nestedBlock = nestedBlock;
73         this.isFirst = isFirst;
74     }
75
76     void accept(Environment env) throws TemplateException, IOException JavaDoc {
77         if (condition == null || condition.isTrue(env)) {
78             if (nestedBlock != null) {
79                 env.visit(nestedBlock);
80             }
81         }
82     }
83
84     public String JavaDoc getCanonicalForm() {
85         StringBuffer JavaDoc buf = new StringBuffer JavaDoc();
86         if (condition == null) {
87             buf.append("<#else");
88         }
89         else if (isFirst) {
90             buf.append("<#if ");
91         }
92         else {
93             buf.append("<#elseif ");
94         }
95         if (condition != null) {
96             buf.append(condition.getCanonicalForm());
97         }
98         buf.append(">");
99         if (nestedBlock != null) {
100             buf.append(nestedBlock.getCanonicalForm());
101         }
102         if (isSimple) {
103             buf.append("</#if>");
104         }
105         return buf.toString();
106     }
107
108     public String JavaDoc getDescription() {
109         String JavaDoc s = "if ";
110         if (condition == null) {
111             s = "else ";
112         }
113         else if (!isFirst) {
114             s = "elseif ";
115         }
116         String JavaDoc cond = condition != null ? condition.toString() : "";
117         return s + cond;
118     }
119 }
120
Popular Tags