    001    // Copyright 2006, 2007, 2009 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.annotations;
    016
    017    import java.lang.annotation.Documented;
    018    import java.lang.annotation.ElementType;
    019    import java.lang.annotation.Retention;
    020    import static java.lang.annotation.RetentionPolicy.RUNTIME;
    021    import java.lang.annotation.Target;
    022
    023    import static org.apache.tapestry5.ioc.annotations.AnnotationUseContext.*;
    024    import org.apache.tapestry5.ioc.annotations.UseWith;
    025
    026    /**
    027     * Marker annotation for methods that should be executed at the start of rendering the component. This usually includes
    028     * rendering of the component's start tag.
    029     * <p/>
    030     * Such methods may optionally take a {@link org.apache.tapestry5.MarkupWriter} parameter, and may return void or
    031     * boolean. Returning true or void will allow the component to advance into the render template / render body phase. If
    032     * a body is present, the {@link org.apache.tapestry5.annotations.BeforeRenderBody} phase will execute. If a component
    033     * has a template, the {@link BeforeRenderTemplate} phase will execute (and the render body will only occur if the
    034     * template directs so).
    035     * <p/>
    036     * Either way, the {@link org.apache.tapestry5.annotations.AfterRender} phase will execute after the template and/or
    037     * body have rendered. A component with a body but without a template will still see the {@link
    038     * org.apache.tapestry5.annotations.BeforeRenderBody} phase execute.
    039     * <p/>
    040     * Returning false will skip rendering of the template and/or body, and jump directly to the {@link AfterRender} phase.
    041     */
    042    @Target(ElementType.METHOD)
    043    @Retention(RUNTIME)
    044    @Documented
    045    @UseWith({COMPONENT,MIXIN,PAGE})
    046    public @interface BeginRender
    047    {
    048
    049    }