/*

  * 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.el.ELException;

 import javax.faces.FacesException;

 import javax.faces.component.UIComponent;

 import javax.faces.view.facelets.FaceletContext;

 import javax.faces.view.facelets.FaceletException;

 import javax.faces.view.facelets.TagAttribute;

 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;

 /**

  * Sets the specified name and attribute on the parent UIComponent. If the "value" specified is not a literal, it will

  * instead set the ValueExpression on the UIComponent. <p /> See <a target="_new"

  * href="http://java.sun.com/j2ee/javaserverfaces/1.1_01/docs/tlddocs/f/attribute.html">tag documentation</a>.

  * 

  * @see javax.faces.component.UIComponent#getAttributes()

  * @see javax.faces.component.UIComponent#setValueExpression(java.lang.String, javax.el.ValueExpression)

  * @author Jacob Hookom

  * @version $Id$

  */

 @JSFFaceletTag(

         name = "f:attribute",

         bodyContent = "empty", 

         tagClass="org.apache.myfaces.taglib.core.AttributeTag")

 public final class AttributeHandler extends TagHandler

     implements javax.faces.view.facelets.AttributeHandler

 {

     private final TagAttribute _name;

     private final TagAttribute _value;

     /**

      * @param config

      */

     public AttributeHandler(TagConfig config)

     {

         super(config);

         _name = getRequiredAttribute("name");

         _value = getRequiredAttribute("value");

     }

     /*

      * (non-Javadoc)

      * 

      * @see javax.faces.view.facelets.FaceletHandler#apply(javax.faces.view.facelets.FaceletContext, javax.faces.component.UIComponent)

      */

     public void apply(FaceletContext ctx, UIComponent parent) throws IOException, FacesException, FaceletException,

             ELException

     {

         if (parent == null)

         {

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

         }

         // only process if the parent is new to the tree

         if (parent.getParent() == null)

         {

             String n = _name.getValue(ctx);

             if (!parent.getAttributes().containsKey(n))

             {

                 if (_value.isLiteral())

                 {

                     parent.getAttributes().put(n, _value.getValue());

                 }

                 else

                 {

                     parent.setValueExpression(n, _value.getValueExpression(ctx, Object.class));

                 }

             }

         }

     }

     public String getAttributeName(FaceletContext ctx)

     {

         return _name.getValue(ctx);

     }

 }