// Copyright 2009 The Apache Software Foundation

 //

 // Licensed 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.tapestry5.corelib.mixins;

 import org.apache.tapestry5.MarkupWriter;

 import org.apache.tapestry5.annotations.MixinAfter;

 import org.apache.tapestry5.dom.Element;

 /**

  * A mixin that attaches to an element that renders an element.  At the end of the render, if the element is empty, then

  * a non-breaking space ( ) is injected into the element. This is often necessary for proper rendering on the

  * client.

  * <p/>

  * Often used in conjunction with the {@link org.apache.tapestry5.corelib.components.Any} component.

  *

  * @since 5.1.0.0

  */

 @MixinAfter

 public class NotEmpty

 {

     private Element element;

     void beginRender(MarkupWriter writer)

     {

         element = writer.getElement();

     }

     void afterRender()

     {

         if (element.isEmpty())

         {

             element.removeChildren();

             element.raw(" ");

         }

     }

 }