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Java > Open Source Codes > org > apache > velocity > runtime > parser > node > ASTDirective


1 package org.apache.velocity.runtime.parser.node;
2
3 /*
4  * Copyright 2000-2001,2004 The Apache Software Foundation.
5  *
6  * Licensed under the Apache License, Version 2.0 (the "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  * http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18
19 import java.io.Writer JavaDoc;
20 import java.io.IOException JavaDoc;
21
22 import org.apache.velocity.context.InternalContextAdapter;
23 import org.apache.velocity.runtime.directive.Directive;
24 import org.apache.velocity.runtime.parser.Parser;
25
26 import org.apache.velocity.exception.MethodInvocationException;
27 import org.apache.velocity.exception.ParseErrorException;
28 import org.apache.velocity.exception.ResourceNotFoundException;
29
30 /**
31  * This class is responsible for handling the pluggable
32  * directives in VTL. ex. #foreach()
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:jvanzyl@apache.org">Jason van Zyl</a>
38  * @author <a HREF="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
39  * @author <a HREF="mailto:kav@kav.dk">Kasper Nielsen</a>
40  * @version $Id: ASTDirective.java,v 1.21.4.1 2004/03/03 23:22:58 geirm Exp $
41  */
42 public class ASTDirective extends SimpleNode
43 {
44     private Directive directive;
45     private String JavaDoc directiveName = "";
46     private boolean isDirective;
47
48     public ASTDirective(int id)
49     {
50         super(id);
51     }
52
53     public ASTDirective(Parser p, int id)
54     {
55         super(p, id);
56     }
57
58
59     /** Accept the visitor. **/
60     public Object JavaDoc jjtAccept(ParserVisitor visitor, Object JavaDoc data)
61     {
62         return visitor.visit(this, data);
63     }
64     
65     public Object JavaDoc init( InternalContextAdapter context, Object JavaDoc data)
66         throws Exception JavaDoc
67     {
68         super.init( context, data );
69
70         /*
71          * only do things that are not context dependant
72          */
73
74         if (parser.isDirective( directiveName ))
75         {
76             isDirective = true;
77             
78             directive = (Directive) parser.getDirective( directiveName )
79                 .getClass().newInstance();
80     
81             directive.init(rsvc, context,this);
82
83             directive.setLocation( getLine(), getColumn() );
84         }
85         else if (rsvc.isVelocimacro( directiveName, context.getCurrentTemplateName() ))
86         {
87             /*
88              * we seem to be a Velocimacro.
89              */
90
91             isDirective = true;
92             directive = (Directive) rsvc.getVelocimacro( directiveName, context.getCurrentTemplateName() );
93
94             directive.init( rsvc, context, this );
95             directive.setLocation( getLine(), getColumn() );
96         }
97         else
98         {
99             isDirective = false;
100         }
101     
102         return data;
103     }
104
105     public boolean render( InternalContextAdapter context, Writer JavaDoc writer)
106         throws IOException JavaDoc,MethodInvocationException, ResourceNotFoundException, ParseErrorException
107     {
108         /*
109          * normal processing
110          */
111
112         if (isDirective)
113         {
114             directive.render(context, writer, this);
115         }
116         else
117         {
118             writer.write( "#");
119             writer.write( directiveName );
120         }
121
122         return true;
123     }
124
125     /**
126      * Sets the directive name. Used by the parser. This keeps us from having to
127      * dig it out of the token stream and gives the parse the change to override.
128      */
129     public void setDirectiveName( String JavaDoc str )
130     {
131         directiveName = str;
132         return;
133     }
134
135     /**
136      * Gets the name of this directive.
137      */
138     public String JavaDoc getDirectiveName()
139     {
140         return directiveName;
141     }
142 }
143
144
145
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