    001    // Copyright 2007, 2008, 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.internal.transform;
    016
    017    import org.apache.tapestry5.MarkupWriter;
    018    import org.apache.tapestry5.internal.InternalComponentResources;
    019    import org.apache.tapestry5.model.MutableComponentModel;
    020    import org.apache.tapestry5.plastic.MethodDescription;
    021    import org.apache.tapestry5.plastic.PlasticClass;
    022    import org.apache.tapestry5.plastic.PlasticField;
    023    import org.apache.tapestry5.plastic.PlasticUtils;
    024    import org.apache.tapestry5.runtime.RenderCommand;
    025    import org.apache.tapestry5.runtime.RenderQueue;
    026    import org.apache.tapestry5.services.TransformConstants;
    027    import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
    028    import org.apache.tapestry5.services.transform.TransformationSupport;
    029
    030    /**
    031     * Ensures that all components implement {@link RenderCommand} by delegating to
    032     * {@link InternalComponentResources#render(org.apache.tapestry5.MarkupWriter, org.apache.tapestry5.runtime.RenderQueue)}.
    033     * This is also responsible for invoking {@link org.apache.tapestry5.internal.InternalComponentResources#postRenderCleanup()}
    034     */
    035    public class RenderCommandWorker implements ComponentClassTransformWorker2
    036    {
    037
    038        private final MethodDescription RENDER_DESCRIPTION = PlasticUtils.getMethodDescription(RenderCommand.class, "render", MarkupWriter.class, RenderQueue.class);
    039
    040        public void transform(PlasticClass plasticClass, TransformationSupport support, MutableComponentModel model)
    041        {
    042            // Subclasses don't need to bother, they'll inherit from super-classes.
    043
    044            if (!support.isRootTransformation())
    045            {
    046                return;
    047            }
    048
    049            plasticClass.introduceInterface(RenderCommand.class);
    050
    051            PlasticField resourcesField = plasticClass.introduceField(InternalComponentResources.class, "resources").injectFromInstanceContext();
    052
    053            plasticClass.introduceMethod(RENDER_DESCRIPTION).delegateTo(resourcesField);
    054
    055            plasticClass.introduceMethod(TransformConstants.POST_RENDER_CLEANUP_DESCRIPTION).delegateTo(resourcesField);
    056        }
    057    }