// Copyright 2007, 2008, 2010 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.apache.tapestry5.internal.services;
import org.apache.tapestry5.TrackableComponentEventCallback;
import org.apache.tapestry5.ContentType;
import org.apache.tapestry5.EventConstants;
import org.apache.tapestry5.internal.InternalConstants;
import org.apache.tapestry5.internal.structure.ComponentPageElement;
import org.apache.tapestry5.internal.structure.Page;
import org.apache.tapestry5.internal.util.Holder;
import org.apache.tapestry5.ioc.internal.util.TapestryException;
import org.apache.tapestry5.json.JSONObject;
import org.apache.tapestry5.services.*;
import java.io.IOException;
/**
* Similar to {@link ComponentEventRequestHandlerImpl}, but built around the Ajax request cycle, where the action
* request sends back an immediate JSON response containing the new content.
*/
@SuppressWarnings("unchecked")
public class AjaxComponentEventRequestHandler implements ComponentEventRequestHandler
{
private final RequestPageCache cache;
private final Request request;
private final PageRenderQueue queue;
private final ComponentEventResultProcessor resultProcessor;
private final PageContentTypeAnalyzer pageContentTypeAnalyzer;
private final Environment environment;
private final AjaxPartialResponseRenderer partialRenderer;
private final PageActivator pageActivator;
public AjaxComponentEventRequestHandler(RequestPageCache cache, Request request, PageRenderQueue queue, @Ajax
ComponentEventResultProcessor resultProcessor, PageActivator pageActivator,
PageContentTypeAnalyzer pageContentTypeAnalyzer, Environment environment,
AjaxPartialResponseRenderer partialRenderer)
{
this.cache = cache;
this.queue = queue;
this.resultProcessor = resultProcessor;
this.pageActivator = pageActivator;
this.pageContentTypeAnalyzer = pageContentTypeAnalyzer;
this.request = request;
this.environment = environment;
this.partialRenderer = partialRenderer;
}
public void handle(ComponentEventRequestParameters parameters) throws IOException
{
Page activePage = cache.get(parameters.getActivePageName());
final Holder<Boolean> resultProcessorInvoked = Holder.create();
resultProcessorInvoked.put(false);
ComponentEventResultProcessor interceptor = new ComponentEventResultProcessor()
{
public void processResultValue(Object value) throws IOException
{
resultProcessorInvoked.put(true);
resultProcessor.processResultValue(value);
}
};
if (pageActivator.activatePage(activePage.getRootElement().getComponentResources(), parameters
.getPageActivationContext(), interceptor))
return;
// If we end up doing a partial render, the page render queue service needs to know the
// page that will be rendered (for logging purposes, if nothing else).
queue.setRenderingPage(activePage);
ContentType contentType = pageContentTypeAnalyzer.findContentType(activePage);
request.setAttribute(InternalConstants.CONTENT_TYPE_ATTRIBUTE_NAME, contentType);
Page containerPage = cache.get(parameters.getContainingPageName());
ComponentPageElement element = containerPage.getComponentElementByNestedId(parameters.getNestedComponentId());
// In many cases, the triggered element is a Form that needs to be able to
// pass its event handler return values to the correct result processor.
// This is certainly the case for forms.
TrackableComponentEventCallback callback = new ComponentResultProcessorWrapper(interceptor);
environment.push(ComponentEventResultProcessor.class, interceptor);
environment.push(TrackableComponentEventCallback.class, callback);
boolean handled = element
.triggerContextEvent(parameters.getEventType(), parameters.getEventContext(), callback);
if (!handled)
throw new TapestryException(ServicesMessages.eventNotHandled(element, parameters.getEventType()), element,
null);
environment.pop(TrackableComponentEventCallback.class);
environment.pop(ComponentEventResultProcessor.class);
if (queue.isPartialRenderInitialized())
{
partialRenderer.renderPartialPageMarkup();
return;
}
// If some other form of return value that's not a partial page render was send through to the
// Ajax ComponentEventResultProcessor, then there's nothing more to do.
if (resultProcessorInvoked.get())
return;
// Send an empty JSON reply if no value was returned from the component event handler method.
JSONObject reply = new JSONObject();
resultProcessor.processResultValue(reply);
}
}