1   /*
    2    * $Id: XmlDefinitionsSet.java 54929 2004-10-16 16:38:42Z germuska $ 
    3    *
    4    * Copyright 1999-2004 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   
   20   package org.apache.struts.tiles.xmlDefinition;
   21   
   22   import java.util.HashMap;
   23   import java.util.Iterator;
   24   import java.util.Map;
   25   
   26   import org.apache.struts.tiles.NoSuchDefinitionException;
   27   
   28   /**
   29    * A set of definitions read from XML definitions file.
   30   */
   31   public class XmlDefinitionsSet
   32   {
   33       /** Defined definitions. */
   34     protected Map definitions;
   35   
   36        /**
   37         * Constructor.
   38         */
   39     public XmlDefinitionsSet()
   40      {
   41      definitions = new HashMap();
   42      }
   43   
   44     /**
   45      * Put definition in set.
   46      * @param definition Definition to add.
   47      */
   48     public void putDefinition(XmlDefinition definition)
   49     {
   50     definitions.put( definition.getName(), definition );
   51     }
   52   
   53     /**
   54      * Get requested definition.
   55      * @param name Definition name.
   56      */
   57     public XmlDefinition getDefinition(String name)
   58     {
   59     return (XmlDefinition)definitions.get( name );
   60     }
   61   
   62     /**
   63      * Get definitions map.
   64      */
   65     public Map getDefinitions()
   66     {
   67     return definitions;
   68     }
   69   
   70     /**
   71      * Resolve extended instances.
   72      */
   73     public void resolveInheritances() throws NoSuchDefinitionException
   74       {
   75         // Walk through all definitions and resolve individual inheritance
   76       Iterator i = definitions.values().iterator();
   77       while( i.hasNext() )
   78         {
   79         XmlDefinition definition = (XmlDefinition)i.next();
   80         definition.resolveInheritance( this );
   81         }  // end loop
   82       }
   83   
   84     /**
   85      * Add definitions from specified child definitions set.
   86      * For each definition in child, look if it already exists in this set.
   87      * If not, add it, if yes, overload parent's definition with child definition.
   88      * @param child Definition used to overload this object.
   89      */
   90     public void extend( XmlDefinitionsSet child )
   91       {
   92       if(child==null)
   93         return;
   94       Iterator i = child.getDefinitions().values().iterator();
   95       while( i.hasNext() )
   96         {
   97         XmlDefinition childInstance = (XmlDefinition)i.next();
   98         XmlDefinition parentInstance = getDefinition(childInstance.getName() );
   99         if( parentInstance != null )
  100           {
  101           parentInstance.overload( childInstance );
  102           }
  103          else
  104           putDefinition( childInstance );
  105         } // end loop
  106       }
  107       /**
  108        * Get String representation.
  109        */
  110     public String toString()
  111       {
  112       return "definitions=" + definitions.toString() ;
  113       }
  114   
  115   }