    001// Copyright 2006, 2009, 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
    015package org.apache.tapestry5.runtime;
    016
    017import org.apache.tapestry5.MarkupWriter;
    018import org.apache.tapestry5.annotations.OnEvent;
    019
    020/**
    021 * Interface that defines the lifecycle of a component, within a page, allowing for callbacks into the component for
    022 * many different events. This interface is part of the public API for Tapestry, but is <em>not</em> expected to be
    023 * directly implemented by component classes; it should only be implemented as part of the component class
    024 * transformation process.
    025 * <p/>
    026 * Most of the methods are related to render phases; see the corresponding annotations and component rendering
    027 * documentation to see how they relate to each other.
    028 * <p/>
    029 * Starting in 5.3 this interface no longer implements {@link PageLifecycleListener}. Normally, this would be an incompatible
    030 * change, but Component is not supposed to be directly implemented by user code.
    031 */
    032public interface Component extends ComponentResourcesAware
    033{
    034
    035    /**
    036     * Lifecycle method invoked at the end of the {@link org.apache.tapestry5.annotations.CleanupRender} render phase.
    037     * There is no annotation for this method, it is part of CleanupRender, but is always invoked. Its specific use is
    038     * to allow components to clean up cached parameter values.
    039     */
    040    void postRenderCleanup();
    041
    042    /**
    043     * Invoked before rendering a component (or its template).
    044     */
    045    void setupRender(MarkupWriter writer, Event event);
    046
    047    /**
    048     * Invoked to allow a component to render its tag (start tag and attributes).
    049     */
    050    void beginRender(MarkupWriter writer, Event event);
    051
    052    /**
    053     * This phase is only invoked for components with templates.
    054     */
    055    void beforeRenderTemplate(MarkupWriter writer, Event event);
    056
    057    /**
    058     * Invoked after rendering the template for a component (only for components with a template).
    059     */
    060    void afterRenderTemplate(MarkupWriter writer, Event event);
    061
    062    /**
    063     * Invoked just before rendering the body of component.
    064     */
    065    void beforeRenderBody(MarkupWriter writer, Event event);
    066
    067    /**
    068     * Invoked just after rendering the body of the component.
    069     */
    070    void afterRenderBody(MarkupWriter writer, Event event);
    071
    072    /**
    073     * Generally used to write the close tag matching any open tag written by {@link
    074     * #beginRender(org.apache.tapestry5.MarkupWriter, Event)}.
    075     */
    076    void afterRender(MarkupWriter writer, Event event);
    077
    078    /**
    079     * Generally used to perform final cleanup of the component after rendering.
    080     */
    081    void cleanupRender(MarkupWriter writer, Event event);
    082
    083    /**
    084     * Invoked to handle a component event. Methods with the {@link OnEvent} annotation (or the matching naming
    085     * convention) will be invoked until one returns a non-null value.
    086     *
    087     * @param event
    088     * @return true if any handler was found (and invoked), false otherwise
    089     * @throws RuntimeException wrapping any checked exceptions that are thrown by individual event handler methods
    090     */
    091    boolean dispatchComponentEvent(ComponentEvent event);
    092}