001    // Copyright 2009 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.services;
016    
017    import java.io.IOException;
018    
019    /**
020     * Filter interface for {@link org.apache.tapestry5.services.ComponentRequestHandler}.
021     */
022    public interface ComponentRequestFilter
023    {
024        /**
025         * Handler for a component action request which will trigger an event on a component and use the return value to
026         * send a response to the client (typically, a redirect to a page render URL).
027         *
028         * @param parameters defining the requst
029         * @param handler    next handler in the pipeline
030         */
031        void handleComponentEvent(ComponentEventRequestParameters parameters, ComponentRequestHandler handler)
032                throws IOException;
033    
034        /**
035         * Invoked to activate and render a page. In certain cases, based on values returned when activating the page, a
036         * {@link org.apache.tapestry5.services.ComponentEventResultProcessor} may be used to send an alternate response
037         * (typically, a redirect).
038         *
039         * @param parameters defines the page name and activation context
040         * @param handler    next handler in the pipeline
041         */
042        void handlePageRender(PageRenderRequestParameters parameters, ComponentRequestHandler handler) throws IOException;
043    }