/*

  * 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.view.facelets.tag.jsf.core;

 import java.io.IOException;

 import javax.faces.component.UIComponent;

 import javax.faces.component.UIPanel;

 import javax.faces.component.UIViewRoot;

 import javax.faces.view.facelets.FaceletContext;

 import javax.faces.view.facelets.TagConfig;

 import javax.faces.view.facelets.TagException;

 import javax.faces.view.facelets.TagHandler;

 import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFFaceletTag;

 import org.apache.myfaces.view.facelets.FaceletCompositionContext;

 import org.apache.myfaces.view.facelets.tag.jsf.ComponentSupport;

 /**

  * Defines the view metadata. It is expected that this tag contains only

  * one or many f:viewParam tags.

  * 

  * @author Leonardo Uribe (latest modification by $Author$)

  * @version $Revision$ $Date$

  */

 @JSFFaceletTag(name="f:metadata")

 public final class ViewMetadataHandler extends TagHandler

 {

     public ViewMetadataHandler(TagConfig config)

     {

         super(config);

     }

     public void apply(FaceletContext ctx, UIComponent parent)

             throws IOException

     {

         if (parent == null)

         {

             throw new TagException(this.tag, "Parent UIComponent was null");

         }

         if (! (parent instanceof UIViewRoot) )

         {

             throw new TagException(this.tag, "Parent UIComponent "+parent.getId()+" should be instance of UIViewRoot");

         }

         FaceletCompositionContext mctx = FaceletCompositionContext.getCurrentInstance(ctx);

         if (mctx.isBuildingViewMetadata())

         {

             UIComponent metadataFacet = parent.getFacet(UIViewRoot.METADATA_FACET_NAME);

             if (metadataFacet == null)

             {

                 metadataFacet = ctx.getFacesContext().getApplication().createComponent(

                         ctx.getFacesContext(), UIPanel.COMPONENT_TYPE, null);

                 metadataFacet.setId(UIViewRoot.METADATA_FACET_NAME);

                 metadataFacet.getAttributes().put(ComponentSupport.FACET_CREATED_UIPANEL_MARKER, true);

                 metadataFacet.getAttributes().put(ComponentSupport.COMPONENT_ADDED_BY_HANDLER_MARKER, Boolean.TRUE);

                 parent.getFacets().put(UIViewRoot.METADATA_FACET_NAME, metadataFacet);

             }

         }

         // We have to do nextHandler.apply() in any case, because even if we're not building ViewMetadata

         // we still need to do it so that the mark/delete components can be applied correctly.

         // (The only tag that needs to do something special is f:event, because in this case

         // ComponentHandler.isNew(parent) does not work for UIViewRoot.)

         parent.getAttributes().put(FacetHandler.KEY, UIViewRoot.METADATA_FACET_NAME);

         mctx.startMetadataSection();

         try

         {

             this.nextHandler.apply(ctx, parent);

         }

         finally

         {

             mctx.endMetadataSection();

             parent.getAttributes().remove(FacetHandler.KEY);

         }

     }

 }