// Copyright 2008, 2009, 2012 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.ComponentEventCallback;
import org.apache.tapestry5.EventConstants;
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.annotations.PostInjection;
import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
import org.apache.tapestry5.ioc.services.TypeCoercer;
import org.apache.tapestry5.model.ComponentModel;
import org.apache.tapestry5.services.ComponentClasses;
import org.apache.tapestry5.services.InvalidationEventHub;
import org.apache.tapestry5.services.InvalidationListener;
import java.util.Map;
public class PageActivationContextCollectorImpl implements PageActivationContextCollector
{
private final Object[] EMPTY = new Object[0];
private final TypeCoercer typeCoercer;
private final ComponentModelSource modelSource;
private final RequestPageCache requestPageCache;
/**
* Keyed on *canonical* page name, value indicates whether the page has a passivate event handler.
*/
private final Map<String, Boolean> cache = CollectionFactory.newConcurrentMap();
public PageActivationContextCollectorImpl(TypeCoercer typeCoercer, RequestPageCache requestPageCache,
ComponentModelSource modelSource)
{
this.typeCoercer = typeCoercer;
this.requestPageCache = requestPageCache;
this.modelSource = modelSource;
}
@PostInjection
public void setupInvalidation(@ComponentClasses InvalidationEventHub invalidationEventHub)
{
invalidationEventHub.clearOnInvalidation(cache);
}
public Object[] collectPageActivationContext(String pageName)
{
Boolean hasHandler = cache.get(pageName);
if (hasHandler == null)
{
ComponentModel model = modelSource.getPageModel(pageName);
hasHandler = model.handlesEvent(EventConstants.PASSIVATE);
cache.put(pageName, hasHandler);
}
// If no handler for the event, then no need to fire the event (and more importantly,
// no need to obtain a page instance!)
if (!hasHandler)
return EMPTY;
// Get or create a page instance and trigger the event.
Page page = requestPageCache.get(pageName);
ComponentPageElement element = page.getRootElement();
final Holder<Object[]> holder = Holder.create();
ComponentEventCallback callback = new ComponentEventCallback()
{
public boolean handleResult(Object result)
{
holder.put(typeCoercer.coerce(result, Object[].class));
// We've got the value, stop the event.
return true;
}
};
element.triggerEvent(EventConstants.PASSIVATE, null, callback);
if (!holder.hasValue()) return EMPTY;
return holder.get();
}
}