    001    // Copyright 2007, 2008, 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.components;
    016
    017    import org.apache.tapestry5.Block;
    018    import org.apache.tapestry5.ComponentResources;
    019    import org.apache.tapestry5.annotations.InjectContainer;
    020    import org.apache.tapestry5.annotations.Parameter;
    021    import org.apache.tapestry5.annotations.SupportsInformalParameters;
    022    import org.apache.tapestry5.ioc.annotations.Inject;
    023    import org.apache.tapestry5.runtime.Component;
    024
    025    /**
    026     * A component that does not do any rendering of its own, but will delegate to some other object that can do rendering.
    027     * This other object may be a component or a {@link Block} (among other things).
    028     * <p>
    029     * This component may also be used to create inline components. For each informal parameter the value will be stored as a
    030     * render variable. To create an inline component, create a block
    031     * and use Delegate multiple times in the template to render the block passing parameters to Delegate. In the block body
    032     * reference the render variables using the "var:" binding prefix and the name of the parameter.
    033     * <p>
    034     * Note that the default binding prefix for informal parameter values is "literal".
    035     *
    036     * @tapestrydoc
    037     */
    038    @SupportsInformalParameters
    039    public class Delegate
    040    {
    041        /**
    042         * The object which will be rendered in place of the Delegate component. This is typically a specific component
    043         * instance, or a {@link Block}.
    044         */
    045        @Parameter(required = true)
    046        private Object to;
    047
    048            @Inject private ComponentResources resources;
    049            @InjectContainer private Component container;
    050
    051            Object beginRender()
    052            {
    053            for(String name : resources.getInformalParameterNames()) {
    054                    Object value = resources.getInformalParameter(name, Object.class);
    055                    container.getComponentResources().storeRenderVariable(name, value);
    056            }
    057
    058            return to;
    059        }
    060    }