// Copyright 2006, 2009 The Apache Software Foundation

 //

 // Licensed under the Apache License, Version 2.0 (the "License");

 // you may not use this file except in compliance with the License.

 // You may obtain a copy of the License at

 //

 //     http://www.apache.org/licenses/LICENSE-2.0

 //

 // Unless required by applicable law or agreed to in writing, software

 // distributed under the License is distributed on an "AS IS" BASIS,

 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 // See the License for the specific language governing permissions and

 // limitations under the License.

 package org.apache.tapestry5.runtime;

 import org.apache.tapestry5.MarkupWriter;

 import org.apache.tapestry5.annotations.OnEvent;

 /**

  * Interface that defines the lifecycle of a component, within a page, allowing for callbacks into the component for

  * many different events. This interface is part of the public API for Tapestry, but is <em>not</em> expected to be

  * directly implemented by component classes; it should only be implemented as part of the component class

  * transformation process.

  * <p/>

  * Most of the methods are related to render phases; see the corresponding annotations and component rendering

  * documentation to see how they relate to each other.

  */

 public interface Component extends ComponentResourcesAware, PageLifecycleListener

 {

     /**

      * Lifecycle method invoked at the end of the {@link org.apache.tapestry5.annotations.CleanupRender} render phase.

      * There is no annotation for this method, it is part of CleanupRender, but is always invoked. Its specific use is

      * to allow components to clean up cached parameter values.

      */

     void postRenderCleanup();

     /**

      * Invoked before rendering a component (or its template).

      */

     void setupRender(MarkupWriter writer, Event event);

     /**

      * Invoked to allow a component to render its tag (start tag and attributes).

      */

     void beginRender(MarkupWriter writer, Event event);

     /**

      * This phase is only invoked for components with templates.

      */

     void beforeRenderTemplate(MarkupWriter writer, Event event);

     /**

      * Invoked after rendering the template for a component (only for components with a template).

      */

     void afterRenderTemplate(MarkupWriter writer, Event event);

     /**

      * Invoked just before rendering the body of component.

      */

     void beforeRenderBody(MarkupWriter writer, Event event);

     /**

      * Invoked just after rendering the body of the component.

      */

     void afterRenderBody(MarkupWriter writer, Event event);

     /**

      * Generally used to write the close tag matching any open tag written by {@link

      * #beginRender(org.apache.tapestry5.MarkupWriter, Event)}.

      */

     void afterRender(MarkupWriter writer, Event event);

     /**

      * Generally used to perform final cleanup of the component after rendering.

      */

     void cleanupRender(MarkupWriter writer, Event event);

     /**

      * Invoked to handle a component event. Methods with the {@link OnEvent} annotation (or the matching naming

      * convention) will be invoked until one returns a non-null value.

      *

      * @param event

      * @return true if any handler was found (and invoked), false otherwise

      * @throws RuntimeException wrapping any checked exceptions that are thrown by individual event handler methods

      */

     boolean dispatchComponentEvent(ComponentEvent event);

 }