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
015package org.apache.tapestry5.internal.services;
016
017import java.io.IOException;
018
019import org.apache.tapestry5.beanmodel.services.*;
020import org.apache.tapestry5.http.services.Request;
021import org.apache.tapestry5.services.Ajax;
022import org.apache.tapestry5.services.ComponentEventRequestFilter;
023import org.apache.tapestry5.services.ComponentEventRequestHandler;
024import org.apache.tapestry5.services.ComponentEventRequestParameters;
025
026/**
027 * A filter that intercepts Ajax-oriented requests, thos that originate on the client-side using XmlHttpRequest. In
028 * these cases, the action processing occurs normally, but the response is quite different.
029 */
030public class AjaxFilter implements ComponentEventRequestFilter
031{
032    private final Request request;
033
034    private final ComponentEventRequestHandler ajaxHandler;
035
036    public AjaxFilter(Request request, @Ajax ComponentEventRequestHandler ajaxHandler)
037    {
038        this.request = request;
039        this.ajaxHandler = ajaxHandler;
040    }
041
042    public void handle(ComponentEventRequestParameters parameters, ComponentEventRequestHandler handler)
043            throws IOException
044    {
045        ComponentEventRequestHandler next = request.isXHR() ? ajaxHandler : handler;
046
047        next.handle(parameters);
048    }
049
050}