2009/05/20 - Apache Shale has been retired.

 /*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to you under the Apache License, Version 2.0

  * (the "License"); you may not use this file except in compliance with

  * the License.  You may obtain a copy of the License at

  *

  *      http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.apache.shale.dialog.faces;

 import java.util.Map;

 import javax.faces.context.FacesContext;

 import javax.faces.el.EvaluationException;

 import javax.faces.el.VariableResolver;

 import org.apache.shale.dialog.Constants;

 import org.apache.shale.dialog.DialogContext;

 /**

  * <p>Variable resolver that provides access to the instance data for a

  * particular {@link DialogContext} instance with a single symbol.</p>

  *

  * @since 1.1

  */

 public final class DialogVariableResolver extends VariableResolver {

     // ------------------------------------------------------------ Constructors

     /**

      * <p>Wrap the specified <code>VariableResolver</code> instance.</p>

      *

      * @param original Original instance to be wrapped

      */

     public DialogVariableResolver(VariableResolver original) {

         this.original = original;

     }

     // ------------------------------------------------------ Instance Variables

     /**

      * <p>The <code>VariableResolver</code> to which we should delegate for

      * variable names other than the one of interest.</p>

      */

     private VariableResolver original = null;

     // ---------------------------------------------------------- Public Methods

     /**

      * <p>Resolve a reference to our dialog instance data (if requested), or

      * delegate to the original <code>VariableResolver</code>.</p>

      *

      * @param context <code>FacesContext</code> for the current request

      * @param name Name of the variable to resolve

      */

     public Object resolveVariable(FacesContext context, String name)

       throws EvaluationException {

         // Delegate unless we are after a variable name of interest

         if (!Constants.DIALOG_SCOPE.equals(name)) {

             return original.resolveVariable(context, name);

         }

         // Look up and return our instance data object (if any)

         Map map = context.getExternalContext().getRequestMap();

         DialogContext dc = (DialogContext) map.get(Constants.CONTEXT_BEAN);

         if (dc != null) {

             return dc.getData();

         } else {

             return null;

         }

     }

 }