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1   package org.apache.commons.ognl;
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.commons.ognl.enhance.UnsupportedCompilationException;
23  
24  import java.util.ArrayList;
25  import java.util.Enumeration;
26  import java.util.List;
27  
28  /**
29   * $Id: ASTSelectFirst.java 1194869 2011-10-29 11:10:16Z mcucchiara $
30   * @author Luke Blanshard (blanshlu@netscape.net)
31   * @author Drew Davidson (drew@ognl.org)
32   */
33  class ASTSelectFirst
34      extends SimpleNode
35  {
36      public ASTSelectFirst( int id )
37      {
38          super( id );
39      }
40  
41      public ASTSelectFirst( OgnlParser p, int id )
42      {
43          super( p, id );
44      }
45  
46      protected Object getValueBody( OgnlContext context, Object source )
47          throws OgnlException
48      {
49          Node expr = children[0];
50          List answer = new ArrayList();
51          ElementsAccessor elementsAccessor = OgnlRuntime.getElementsAccessor( OgnlRuntime.getTargetClass( source ) );
52  
53          for ( Enumeration e = elementsAccessor.getElements( source ); e.hasMoreElements(); )
54          {
55              Object next = e.nextElement();
56  
57              if ( OgnlOps.booleanValue( expr.getValue( context, next ) ) )
58              {
59                  answer.add( next );
60                  break;
61              }
62          }
63          return answer;
64      }
65  
66      public String toGetSourceString( OgnlContext context, Object target )
67      {
68          throw new UnsupportedCompilationException( "Eval expressions not supported as native java yet." );
69      }
70  
71      public String toSetSourceString( OgnlContext context, Object target )
72      {
73          throw new UnsupportedCompilationException( "Eval expressions not supported as native java yet." );
74      }
75      
76      public <R, P> R accept( NodeVisitor<? extends R, ? super P> visitor, P data )
77          throws OgnlException
78      {
79          return visitor.visit( this, data );
80      }
81  }