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}