001    // Copyright 2010, 2011 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    // http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.corelib.mixins;
016    
017    import org.apache.tapestry5.Block;
018    import org.apache.tapestry5.ComponentResources;
019    import org.apache.tapestry5.MarkupWriter;
020    import org.apache.tapestry5.annotations.AfterRender;
021    import org.apache.tapestry5.annotations.BeginRender;
022    import org.apache.tapestry5.annotations.Events;
023    import org.apache.tapestry5.ioc.annotations.Inject;
024    
025    /**
026     * This mixin triggers event notifcations to identify when it enters
027     * the {@link BeginRender} and {@link AfterRender} render phases.
028     * The {@link MarkupWriter} is passed as the event context. The most common use of this
029     * is to handle the "afterRender" event to generate client-side JavaScript for content
030     * just rendered via a {@link Block} (this is a common Ajax use case related to partial
031     * page rendering).
032     * 
033     * @since 5.2.0
034     * @tapestrydoc
035     */
036    @Events(
037    { "beginRender", "afterRender" })
038    public class RenderNotification
039    {
040        @Inject
041        private ComponentResources resources;
042    
043        void beginRender(MarkupWriter writer)
044        {
045            trigger(writer, "beginRender");
046        }
047    
048        void afterRender(MarkupWriter writer)
049        {
050            trigger(writer, "afterRender");
051        }
052    
053        private void trigger(MarkupWriter writer, String eventName)
054        {
055            resources.triggerEvent(eventName, new Object[]
056            { writer }, null);
057        }
058    }