/*

  * 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.myfaces.el.unified.resolver.implicitobject;

 import java.beans.FeatureDescriptor;

 import javax.el.ELContext;

 import javax.el.ELResolver;

 import javax.faces.context.ExternalContext;

 import javax.faces.context.FacesContext;

 /**

  * Implementors of this class encapsulate the information needed to resolve

  * the implicit object.

  *

  * @author Stan Silvert

  */

 public abstract class ImplicitObject {

     public abstract Object getValue(ELContext context);

     public abstract FeatureDescriptor getDescriptor();

     /**

      * Returns an interned String representing the name of the 

      * implicit object.

      */

     public abstract String getName();

     /**

      * Returns the most general type allowed for a future call to setValue()

      */

     public abstract Class getType();

     protected FeatureDescriptor makeDescriptor(String name, 

                                                String description, 

                                                Class elResolverType) {

         FeatureDescriptor fd = new FeatureDescriptor();

         fd.setValue(ELResolver.RESOLVABLE_AT_DESIGN_TIME, Boolean.TRUE);

         fd.setValue(ELResolver.TYPE, elResolverType);

         fd.setName(name);

         fd.setDisplayName(name);

         fd.setShortDescription(description);

         fd.setExpert(false);

         fd.setHidden(false);

         fd.setPreferred(true);

         return fd;

     }

     // get the FacesContext from the ELContext

     protected FacesContext facesContext(ELContext context) {

         return (FacesContext)context.getContext(FacesContext.class);

     }

     protected ExternalContext externalContext(ELContext context) {

         return facesContext(context).getExternalContext();

     }

 }