    001// Licensed under the Apache License, Version 2.0 (the "License");
    002// you may not use this file except in compliance with the License.
    003// You may obtain a copy of the License at
    004//
    005// http://www.apache.org/licenses/LICENSE-2.0
    006//
    007// Unless required by applicable law or agreed to in writing, software
    008// distributed under the License is distributed on an "AS IS" BASIS,
    009// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    010// See the License for the specific language governing permissions and
    011// limitations under the License.
    012
    013package org.apache.tapestry5.internal.services;
    014
    015import org.apache.tapestry5.TrackableComponentEventCallback;
    016import org.apache.tapestry5.internal.structure.ComponentPageElement;
    017import org.apache.tapestry5.internal.structure.Page;
    018import org.apache.tapestry5.ioc.annotations.Primary;
    019import org.apache.tapestry5.ioc.internal.util.TapestryException;
    020import org.apache.tapestry5.services.*;
    021
    022import java.io.IOException;
    023
    024@SuppressWarnings("unchecked")
    025public class ComponentEventRequestHandlerImpl implements ComponentEventRequestHandler
    026{
    027    private final ComponentEventResultProcessor resultProcessor;
    028
    029    private final RequestPageCache cache;
    030
    031    private final Response response;
    032
    033    private final PageActivator pageActivator;
    034
    035    private final Environment environment;
    036
    037    public ComponentEventRequestHandlerImpl(@Traditional
    038                                            @Primary
    039                                            ComponentEventResultProcessor resultProcessor,
    040
    041                                            RequestPageCache cache, Response response,
    042
    043                                            PageActivator pageActivator,
    044
    045                                            Environment environment)
    046    {
    047        this.resultProcessor = resultProcessor;
    048        this.cache = cache;
    049        this.response = response;
    050        this.pageActivator = pageActivator;
    051        this.environment = environment;
    052    }
    053
    054    public void handle(ComponentEventRequestParameters parameters) throws IOException
    055    {
    056        Page activePage = cache.get(parameters.getActivePageName());
    057
    058        if (pageActivator.activatePage(activePage.getRootElement().getComponentResources(), parameters
    059                .getPageActivationContext(), resultProcessor))
    060        {
    061            return;
    062        }
    063
    064        Page containerPage = cache.get(parameters.getContainingPageName());
    065
    066        TrackableComponentEventCallback callback = new ComponentResultProcessorWrapper(resultProcessor);
    067
    068        environment.push(ComponentEventResultProcessor.class, resultProcessor);
    069        environment.push(TrackableComponentEventCallback.class, callback);
    070
    071        ComponentPageElement element = containerPage.getComponentElementByNestedId(parameters.getNestedComponentId());
    072
    073        boolean handled = element.triggerContextEvent(parameters.getEventType(), parameters.getEventContext(), callback);
    074
    075        if (!handled)
    076        {
    077            throw new TapestryException(String.format("Request event '%s' (on component %s) was not handled; you must provide a matching event handler method in the component or in one of its containers.", parameters.getEventType(), element.getCompleteId()), element,
    078                    null);
    079        }
    080
    081        environment.pop(TrackableComponentEventCallback.class);
    082        environment.pop(ComponentEventResultProcessor.class);
    083
    084        if (callback.isAborted())
    085        {
    086            callback.rethrow();
    087            return;
    088        }
    089
    090        // If we get this far without generating a response, the default behavior is to
    091        // generate a redirect back to the active page; we can let the ComponentEventResultProcessor handle that.
    092
    093        if (!response.isCommitted())
    094        {
    095            resultProcessor.processResultValue(activePage.getName());
    096        }
    097    }
    098}