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1   /*
2    * Copyright 2002,2004 The Apache Software Foundation.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.commons.jelly.tags.antlr;
18  
19  import org.apache.commons.jelly.XMLOutput;
20  import org.apache.commons.jelly.TagSupport;
21  import org.apache.commons.jelly.JellyTagException;
22  
23  public class GrammarTag extends TagSupport
24  {
25      public GrammarTag()
26      {
27      }
28  
29  
30      // Tag interface
31      //-------------------------------------------------------------------------
32  
33      public void doTag(final XMLOutput output) throws JellyTagException
34      {
35          String grammar = getBodyText();
36  
37          AntlrTag antlr = (AntlrTag) findAncestorWithClass( AntlrTag.class );
38  
39          if ( antlr == null )
40          {
41              throw new JellyTagException( "<grammar> should only be used within an <antlr> block." );
42          }
43  
44          antlr.addGrammar( grammar );
45      }
46  }