/*

  * 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;

 import java.lang.reflect.InvocationTargetException;

 import java.lang.reflect.Method;

 import java.util.ArrayList;

 import java.util.List;

 import javax.el.ArrayELResolver;

 import javax.el.BeanELResolver;

 import javax.el.CompositeELResolver;

 import javax.el.ELResolver;

 import javax.el.ExpressionFactory;

 import javax.el.ListELResolver;

 import javax.el.MapELResolver;

 import javax.el.ResourceBundleELResolver;

 import javax.faces.context.FacesContext;

 import org.apache.myfaces.config.RuntimeConfig;

 import org.apache.myfaces.el.FlashELResolver;

 import org.apache.myfaces.el.unified.resolver.CompositeComponentELResolver;

 import org.apache.myfaces.el.unified.resolver.FacesCompositeELResolver.Scope;

 import org.apache.myfaces.el.unified.resolver.ImportHandlerResolver;

 import org.apache.myfaces.el.unified.resolver.ManagedBeanResolver;

 import org.apache.myfaces.el.unified.resolver.ResourceBundleResolver;

 import org.apache.myfaces.el.unified.resolver.ResourceResolver;

 import org.apache.myfaces.el.unified.resolver.ScopedAttributeResolver;

 import org.apache.myfaces.el.unified.resolver.implicitobject.ImplicitObjectResolver;

 import org.apache.myfaces.shared.config.MyfacesConfig;

 import org.apache.myfaces.shared.util.ClassUtils;

 /**

  * Create the el resolver for faces. see 1.2 spec section 5.6.2

  * 

  * @author Mathias Broekelmann (latest modification by $Author$)

  * @version $Revision$ $Date$

  */

 public class ResolverBuilderForFaces extends ResolverBuilderBase implements ELResolverBuilder

 {

     private static final Class STATIC_FIELD_EL_RESOLVER_CLASS;

     private static final Method GET_STREAM_EL_RESOLVER_METHOD;

     static

     {

         Class staticFieldELResolverClass = null;

         Method getStreamELResolverMethod = null;

         try

         {

             staticFieldELResolverClass = ClassUtils.classForName("javax.el.StaticFieldELResolver");

             getStreamELResolverMethod = ExpressionFactory.class.getMethod("getStreamELResolver");

         }

         catch (NoSuchMethodException ex)

         {

             //No op

         }

         catch (SecurityException ex)

         {

             //No op

         }

         catch (ClassNotFoundException ex)

         {

             //No op

         }

         STATIC_FIELD_EL_RESOLVER_CLASS = staticFieldELResolverClass;

         GET_STREAM_EL_RESOLVER_METHOD = getStreamELResolverMethod;

     }

     public ResolverBuilderForFaces(RuntimeConfig config)

     {

         super(config);

     }

     public void build(CompositeELResolver compositeElResolver)

     {

         // add the ELResolvers to a List first to be able to sort them

         List<ELResolver> list = new ArrayList<ELResolver>();

         list.add(ImplicitObjectResolver.makeResolverForFaces());

         list.add(new CompositeComponentELResolver());

         addFromRuntimeConfig(list);

         //Flash object is instanceof Map, so it is necessary to resolve

         //before MapELResolver. Better to put this one before

         list.add(new FlashELResolver());

         list.add(new ManagedBeanResolver());

         list.add(new ResourceResolver());

         list.add(new ResourceBundleELResolver());

         list.add(new ResourceBundleResolver());

         if (STATIC_FIELD_EL_RESOLVER_CLASS != null &&

             GET_STREAM_EL_RESOLVER_METHOD != null)

         {

             try

             {

                 ELResolver streamElResolver = (ELResolver) GET_STREAM_EL_RESOLVER_METHOD.invoke(

                         getRuntimeConfig().getExpressionFactory());

                 if (streamElResolver != null)

                 {

                     // By default return null, but in a EL 3 implementation it should be there,

                     // this is just to avoid exceptions in junit testing

                     list.add(streamElResolver);

                 }

                 list.add((ELResolver) STATIC_FIELD_EL_RESOLVER_CLASS.newInstance());

             } 

             catch (IllegalAccessException ex)

             {

             }

             catch (IllegalArgumentException ex)

             {

             }

             catch (InvocationTargetException ex)

             {

             }

             catch (InstantiationException ex)

             {

             }

         }

         list.add(new MapELResolver());

         list.add(new ListELResolver());

         list.add(new ArrayELResolver());

         list.add(new BeanELResolver());

         // give the user a chance to sort the resolvers

         sortELResolvers(list, Scope.Faces);

         // give the user a chance to filter the resolvers

         Iterable<ELResolver> filteredELResolvers = filterELResolvers(list, Scope.Faces);

         // add the resolvers from the list to the CompositeELResolver

         for (ELResolver resolver : filteredELResolvers)

         {

             compositeElResolver.add(resolver);

         }

         // Only add this resolver if the user wants to use the EL ImportHandler

         if (MyfacesConfig.getCurrentInstance(

              FacesContext.getCurrentInstance().getExternalContext()).isSupportEL3ImportHandler())

         {

             compositeElResolver.add(new ImportHandlerResolver());

         }

         // the ScopedAttributeResolver has to be the last one in every

         // case, because it always sets propertyResolved to true (per the spec)

         compositeElResolver.add(new ScopedAttributeResolver());

     }

 }