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.beanmodel.services.*;
017import org.apache.tapestry5.commons.internal.util.TapestryException;
018import org.apache.tapestry5.http.services.Response;
019import org.apache.tapestry5.internal.structure.ComponentPageElement;
020import org.apache.tapestry5.internal.structure.Page;
021import org.apache.tapestry5.ioc.annotations.Primary;
022import org.apache.tapestry5.services.ComponentEventRequestHandler;
023import org.apache.tapestry5.services.ComponentEventRequestParameters;
024import org.apache.tapestry5.services.ComponentEventResultProcessor;
025import org.apache.tapestry5.services.Environment;
026import org.apache.tapestry5.services.Traditional;
027
028import java.io.IOException;
029
030@SuppressWarnings("unchecked")
031public class ComponentEventRequestHandlerImpl implements ComponentEventRequestHandler
032{
033    private final ComponentEventResultProcessor resultProcessor;
034
035    private final RequestPageCache cache;
036
037    private final Response response;
038
039    private final PageActivator pageActivator;
040
041    private final Environment environment;
042
043    public ComponentEventRequestHandlerImpl(@Traditional
044                                            @Primary
045                                            ComponentEventResultProcessor resultProcessor,
046
047                                            RequestPageCache cache, Response response,
048
049                                            PageActivator pageActivator,
050
051                                            Environment environment)
052    {
053        this.resultProcessor = resultProcessor;
054        this.cache = cache;
055        this.response = response;
056        this.pageActivator = pageActivator;
057        this.environment = environment;
058    }
059
060    public void handle(ComponentEventRequestParameters parameters) throws IOException
061    {
062        Page activePage = cache.get(parameters.getActivePageName());
063
064        if (pageActivator.activatePage(activePage.getRootElement().getComponentResources(), parameters
065                .getPageActivationContext(), resultProcessor))
066        {
067            return;
068        }
069
070        Page containerPage = cache.get(parameters.getContainingPageName());
071
072        TrackableComponentEventCallback callback = new ComponentResultProcessorWrapper(resultProcessor);
073
074        environment.push(ComponentEventResultProcessor.class, resultProcessor);
075        environment.push(TrackableComponentEventCallback.class, callback);
076
077        ComponentPageElement element = containerPage.getComponentElementByNestedId(parameters.getNestedComponentId());
078
079        boolean handled = element.triggerContextEvent(parameters.getEventType(), parameters.getEventContext(), callback);
080
081        if (!handled)
082        {
083            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,
084                    null);
085        }
086
087        environment.pop(TrackableComponentEventCallback.class);
088        environment.pop(ComponentEventResultProcessor.class);
089
090        if (callback.isAborted())
091        {
092            callback.rethrow();
093            return;
094        }
095
096        // If we get this far without generating a response, the default behavior is to
097        // generate a redirect back to the active page; we can let the ComponentEventResultProcessor handle that.
098
099        if (!response.isCommitted())
100        {
101            resultProcessor.processResultValue(activePage.getName());
102        }
103    }
104}