001    // Copyright 2007, 2008 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.services;
016    
017    import java.io.IOException;
018    
019    /**
020     * Filter interface for {@link PageRenderRequestHandler}, which allows extra behaviors to be injected into the
021     * processing of a page render request.
022     */
023    public interface PageRenderRequestFilter
024    {
025        /**
026         * Invoked to activate and render a page. The return value of the event handler method(s) for the activate event may
027         * result in an action response generator being returned.
028         *
029         * @param parameters defines the page name and activation context
030         * @param handler    to delegate the invocation to
031         */
032        void handle(PageRenderRequestParameters parameters, PageRenderRequestHandler handler) throws IOException;
033    }