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.internal.services;
016    
017    import org.apache.tapestry5.services.*;
018    
019    import java.io.IOException;
020    
021    /**
022     * A filter that intercepts Ajax-oriented requests, thos that originate on the client-side using XmlHttpRequest. In
023     * these cases, the action processing occurs normally, but the response is quite different.
024     */
025    public class AjaxFilter implements ComponentEventRequestFilter
026    {
027        private final Request request;
028    
029        private final ComponentEventRequestHandler ajaxHandler;
030    
031        public AjaxFilter(Request request, @Ajax ComponentEventRequestHandler ajaxHandler)
032        {
033            this.request = request;
034            this.ajaxHandler = ajaxHandler;
035        }
036    
037        public void handle(ComponentEventRequestParameters parameters, ComponentEventRequestHandler handler)
038                throws IOException
039        {
040            ComponentEventRequestHandler next = request.isXHR() ? ajaxHandler : handler;
041    
042            next.handle(parameters);
043        }
044    
045    }