/*
    * 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);
          }
      }
  }