    001// Licensed under the Apache License, Version 2.0 (the "License");
    002// you may not use this file except in compliance with the License.
    003// You may obtain a copy of the License at
    004//
    005//     http://www.apache.org/licenses/LICENSE-2.0
    006//
    007// Unless required by applicable law or agreed to in writing, software
    008// distributed under the License is distributed on an "AS IS" BASIS,
    009// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    010// See the License for the specific language governing permissions and
    011// limitations under the License.
    012
    013package org.apache.tapestry5.corelib.components;
    014
    015import org.apache.tapestry5.Block;
    016import org.apache.tapestry5.ComponentResources;
    017import org.apache.tapestry5.annotations.InjectContainer;
    018import org.apache.tapestry5.annotations.Parameter;
    019import org.apache.tapestry5.annotations.SupportsInformalParameters;
    020import org.apache.tapestry5.ioc.annotations.Inject;
    021import org.apache.tapestry5.runtime.Component;
    022
    023/**
    024 * A component that does not do any rendering of its own, but will delegate to some other object that can do rendering.
    025 * This other object may be a component or a {@link Block} (among other things).
    026 *
    027 * This component may also be used to create inline components. For each informal parameter the value will be stored as a
    028 * render variable. To create an inline component, create a block
    029 * and use Delegate multiple times in the template to render the block passing parameters to Delegate. In the block body
    030 * reference the render variables using the "var:" binding prefix and the name of the parameter.
    031 *
    032 * Note that the default binding prefix for informal parameter values is "literal".
    033 *
    034 * @tapestrydoc
    035 */
    036@SupportsInformalParameters
    037public class Delegate
    038{
    039    /**
    040     * The object which will be rendered in place of the Delegate component. This is typically a specific component
    041     * instance, or a {@link Block}.
    042     */
    043    @Parameter(required = true)
    044    private Object to;
    045
    046    @Inject private ComponentResources resources;
    047    @InjectContainer private Component container;
    048
    049    Object beginRender()
    050    {
    051        for(String name : resources.getInformalParameterNames()) {
    052            Object value = resources.getInformalParameter(name, Object.class);
    053            container.getComponentResources().storeRenderVariable(name, value);
    054        }
    055
    056        return to;
    057    }
    058}