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.annotations;
014
015import org.apache.tapestry5.ioc.annotations.UseWith;
016
017import java.lang.annotation.Documented;
018import java.lang.annotation.ElementType;
019import java.lang.annotation.Retention;
020import java.lang.annotation.Target;
021
022import static java.lang.annotation.RetentionPolicy.RUNTIME;
023import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.*;
024
025/**
026 * Marker annotation for methods that should be executed at the start of rendering the component. This usually includes
027 * rendering of the component's start tag.
028 *
029 * Such methods may optionally take a {@link org.apache.tapestry5.MarkupWriter} parameter, and may return void or
030 * boolean. Returning true or void will allow the component to advance into the render template / render body phase. If
031 * a body is present, the {@link org.apache.tapestry5.annotations.BeforeRenderBody} phase will execute. If a component
032 * has a template, the {@link BeforeRenderTemplate} phase will execute (and the render body will only occur if the
033 * template directs so).
034 *
035 * Either way, the {@link org.apache.tapestry5.annotations.AfterRender} phase will execute after the template and/or
036 * body have rendered. A component with a body but without a template will still see the {@link
037 * org.apache.tapestry5.annotations.BeforeRenderBody} phase execute.
038 *
039 * Returning false will skip rendering of the template and/or body, and jump directly to the {@link AfterRender} phase.
040 */
041@Target(ElementType.METHOD)
042@Retention(RUNTIME)
043@Documented
044@UseWith({COMPONENT,MIXIN,PAGE})
045public @interface BeginRender
046{
047
048}