    001    // Copyright 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.EventConstants;
    018    import org.apache.tapestry5.internal.InternalConstants;
    019    import org.apache.tapestry5.internal.structure.Page;
    020    import org.apache.tapestry5.services.*;
    021
    022    import java.io.IOException;
    023
    024    public class ImmediateActionRenderResponseFilter implements ComponentEventRequestFilter
    025    {
    026        private final Request request;
    027
    028        private final Response response;
    029
    030        private final PageResponseRenderer renderer;
    031
    032        public ImmediateActionRenderResponseFilter(Request request, PageResponseRenderer renderer, Response response)
    033        {
    034            this.request = request;
    035            this.renderer = renderer;
    036            this.response = response;
    037        }
    038
    039        public void handle(ComponentEventRequestParameters parameters, ComponentEventRequestHandler handler)
    040                throws IOException
    041        {
    042            handler.handle(parameters);
    043
    044            // If markup or a redirect has already been generated, then we're good.
    045
    046            if (response.isCommitted()) return;
    047
    048            // Otherwise, we should be operating in immediate mode.  Figure out which page
    049            // was selected to render.
    050
    051            Page page = (Page) request.getAttribute(InternalConstants.IMMEDIATE_RESPONSE_PAGE_ATTRIBUTE);
    052
    053            if (page != null)
    054            {
    055                // We don't have a context to provide but this still nags me as not the right thing to do.
    056
    057                page.getRootElement().triggerEvent(EventConstants.ACTIVATE, new Object[0], null);
    058
    059                renderer.renderPageResponse(page);
    060                return;
    061            }
    062
    063            throw new IllegalStateException(
    064                    "Sanity check - neither a stream response nor a redirect response was generated for this action request.");
    065        }
    066    }