content: /*
   * $Header$
   * $Revision$
   * $Date$
   *
   * ====================================================================
   *
   * Copyright 2000-2002 bob mcwhirter & James Strachan.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   * 
   *   * Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   * 
   *   * Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution.
   * 
   *   * Neither the name of the Jaxen Project nor the names of its
   *     contributors may be used to endorse or promote products derived 
   *     from this software without specific prior written permission.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
   * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
   * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
   * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
   * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * ====================================================================
   * This software consists of voluntary contributions made by many 
   * individuals on behalf of the Jaxen Project and was originally 
   * created by bob mcwhirter <bob@werken.com> and 
   * James Strachan <jstrachan@apache.org>.  For more information on the 
   * Jaxen Project, please see <http://www.jaxen.org/>.
   * 
   * $Id$
   */
  
  
  package org.jaxen;
  
  import java.io.Serializable;
  import java.util.HashMap;
  import java.util.Map;
  
  /** Simple default implementation for <code>VariableContext</code>.
   *
   *  <p>
   *  This is a simple table-based key-lookup implementation
   *  for <code>VariableContext</code> which can be programmatically
   *  extended by setting additional variables.
   *  </p>
   *
   *  @author <a href="mailto:bob@werken.com">bob mcwhirter</a>
   */
  public class SimpleVariableContext implements VariableContext, Serializable
  {
      /**
       * 
       */
      private static final long serialVersionUID = 961322093794516518L;
      /** Table of variable bindings. */
      private Map variables;
  
      /** Construct.
       *
       *  <p>
       *  Create a new empty variable context.
       *  </p>
       */
      public SimpleVariableContext()
      {
          variables = new HashMap();
      }
  
      /** Set the value associated with a variable.
       *
       *  <p>
       *  This method sets a variable that is 
       *  associated with a particular namespace.
       *  These variables appear such as <code>$prefix:foo</code>
       *  in an XPath expression.  Prefix to URI resolution
       *  is the responsibility of a <code>NamespaceContext</code>.
       *  Variables within a <code>VariableContext</code> are
       *  referred to purely based upon their namespace URI,
       *  if any.
       *  </p>
       *
       *  @param namespaceURI the namespace URI of the variable
       *  @param localName the local name of the variable
       *  @param value The value to be bound to the variable
       */
      public void setVariableValue( String namespaceURI,
                                    String localName,
                                    Object value )
      {
          this.variables.put( new QualifiedName(namespaceURI, localName),
                              value );
      }
  
      /** Set the value associated with a variable.
       *
       *  <p>
       *  This method sets a variable that is <strong>not</strong>
       *  associated with any particular namespace.
       *  These variables look like <code>$foo</code>
       *  in an XPath expression.
       *  </p>
       *
       *  @param localName the local name of the variable
       *  @param value the value to be bound to the variable
       */
      public void setVariableValue( String localName,
                                    Object value )
      {
          this.variables.put( new QualifiedName(null, localName), value );
      }
  
      public Object getVariableValue( String namespaceURI,
                                      String prefix,
                                      String localName )
          throws UnresolvableException
      {
          QualifiedName key = new QualifiedName( namespaceURI, localName );
  
          if ( this.variables.containsKey(key) )
          {
              return this.variables.get( key );
          }
          else
          {
              throw new UnresolvableException( "Variable " + key.getClarkForm() );
          }
      }
  }
  