| // Copyright 2008, 2009 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.internal.util.CollectionFactory; |
| import org.apache.tapestry5.ioc.services.TypeCoercer; |
| import org.apache.tapestry5.model.ComponentModel; |
| import org.apache.tapestry5.services.InvalidationListener; |
| |
| import java.util.Map; |
| |
| public class PageActivationContextCollectorImpl implements PageActivationContextCollector, InvalidationListener |
| { |
| 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; |
| } |
| |
| public void objectWasInvalidated() |
| { |
| cache.clear(); |
| } |
| |
| 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(); |
| } |
| } |