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1   /*
2    * $Id: XmlDefinitionsSet.java 471754 2006-11-06 14:55:09Z husted $
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  package org.apache.struts.tiles.xmlDefinition;
23  
24  import java.util.HashMap;
25  import java.util.Iterator;
26  import java.util.Map;
27  
28  import org.apache.struts.tiles.NoSuchDefinitionException;
29  
30  /**
31   * A set of definitions read from XML definitions file.
32  */
33  public class XmlDefinitionsSet
34  {
35      /** Defined definitions. */
36    protected Map definitions;
37  
38       /**
39        * Constructor.
40        */
41    public XmlDefinitionsSet()
42     {
43     definitions = new HashMap();
44     }
45  
46    /**
47     * Put definition in set.
48     * @param definition Definition to add.
49     */
50    public void putDefinition(XmlDefinition definition)
51    {
52    definitions.put( definition.getName(), definition );
53    }
54  
55    /**
56     * Get requested definition.
57     * @param name Definition name.
58     */
59    public XmlDefinition getDefinition(String name)
60    {
61    return (XmlDefinition)definitions.get( name );
62    }
63  
64    /**
65     * Get definitions map.
66     */
67    public Map getDefinitions()
68    {
69    return definitions;
70    }
71  
72    /**
73     * Resolve extended instances.
74     */
75    public void resolveInheritances() throws NoSuchDefinitionException
76      {
77        // Walk through all definitions and resolve individual inheritance
78      Iterator i = definitions.values().iterator();
79      while( i.hasNext() )
80        {
81        XmlDefinition definition = (XmlDefinition)i.next();
82        definition.resolveInheritance( this );
83        }  // end loop
84      }
85  
86    /**
87     * Add definitions from specified child definitions set.
88     * For each definition in child, look if it already exists in this set.
89     * If not, add it, if yes, overload parent's definition with child definition.
90     * @param child Definition used to overload this object.
91     */
92    public void extend( XmlDefinitionsSet child )
93      {
94      if(child==null)
95        return;
96      Iterator i = child.getDefinitions().values().iterator();
97      while( i.hasNext() )
98        {
99        XmlDefinition childInstance = (XmlDefinition)i.next();
100       XmlDefinition parentInstance = getDefinition(childInstance.getName() );
101       if( parentInstance != null )
102         {
103         parentInstance.overload( childInstance );
104         }
105        else
106         putDefinition( childInstance );
107       } // end loop
108     }
109     /**
110      * Get String representation.
111      */
112   public String toString()
113     {
114     return "definitions=" + definitions.toString() ;
115     }
116 
117 }