    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
    015    package org.apache.tapestry5.runtime;
    016
    017    import org.apache.tapestry5.MarkupWriter;
    018    import 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     */
    032    public 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    }