    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}