/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.myfaces.extensions.cdi.jsf2.impl.scope.view;
import org.apache.myfaces.extensions.cdi.core.api.provider.BeanManagerProvider;
import java.lang.annotation.Annotation;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import javax.enterprise.context.ContextNotActiveException;
import javax.enterprise.context.spi.Context;
import javax.enterprise.context.spi.Contextual;
import javax.enterprise.context.spi.CreationalContext;
import javax.enterprise.inject.spi.BeanManager;
import javax.enterprise.inject.spi.PassivationCapable;
import javax.faces.bean.ViewScoped;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
import javax.faces.event.PreDestroyViewMapEvent;
import javax.faces.event.SystemEvent;
import javax.faces.event.SystemEventListener;
/**
* This class provides the contexts lifecycle for the
* new JSF-2 @ViewScoped Context.
*/
public class ViewScopedContext implements Context, SystemEventListener
{
private static final String COMPONENT_ID_MAP_NAME ="codi.componentIdMap";
private static final String CREATIONAL_MAP_NAME ="codi.creationalInstanceMap";
private static final String UNCHECKED = "unchecked";
private boolean isJsfSubscribed = false;
/**
* {@inheritDoc}
*/
public <T> T get(Contextual<T> component)
{
checkActive();
if(!isJsfSubscribed)
{
FacesContext.getCurrentInstance().getApplication().subscribeToEvent(PreDestroyViewMapEvent.class, this);
isJsfSubscribed = true;
}
Map<String, Object> viewMap = getViewMap();
@SuppressWarnings(UNCHECKED)
Map<String, Object> componentIdMap = (Map<String, Object>) viewMap.get(COMPONENT_ID_MAP_NAME);
if(componentIdMap == null)
{
return null;
}
@SuppressWarnings(UNCHECKED)
T instance = (T)componentIdMap.get(((PassivationCapable)component).getId());
return instance;
}
/**
* {@inheritDoc}
*/
public <T> T get(Contextual<T> component, CreationalContext<T> creationalContext)
{
if(!(component instanceof PassivationCapable))
{
throw new IllegalStateException(component.toString() +
" doesn't implement " + PassivationCapable.class.getName());
}
checkActive();
Map<String, Object> viewMap = getViewMap();
@SuppressWarnings(UNCHECKED)
Map<String, Object> componentIdMap = (Map<String, Object>) viewMap.get(COMPONENT_ID_MAP_NAME);
if(componentIdMap == null)
{
// TODO we now need to start being carefull with reentrancy...
componentIdMap = new ConcurrentHashMap<String, Object>();
viewMap.put(COMPONENT_ID_MAP_NAME, componentIdMap);
}
@SuppressWarnings(UNCHECKED)
T instance = (T) componentIdMap.get(((PassivationCapable)component).getId());
if (instance != null)
{
return instance;
}
if(creationalContext == null)
{
return null;
}
instance = component.create(creationalContext);
if (instance == null)
{
return null;
}
@SuppressWarnings(UNCHECKED)
Map<String, CreationalContext<?>> creationalContextMap
= (Map<String, CreationalContext<?>>) viewMap.get(CREATIONAL_MAP_NAME);
if(creationalContextMap == null)
{
creationalContextMap = new ConcurrentHashMap<String, CreationalContext<?>>();
viewMap.put(CREATIONAL_MAP_NAME, creationalContextMap);
}
componentIdMap.put(((PassivationCapable)component).getId(), instance);
creationalContextMap.put(((PassivationCapable)component).getId(), creationalContext);
return instance;
}
/**
* {@inheritDoc}
*/
public Class<? extends Annotation> getScope()
{
return ViewScoped.class;
}
/**
* The view context is active if a valid ViewRoot could be detected.
*/
public boolean isActive()
{
return getViewRoot() != null;
}
private void checkActive()
{
if (!isActive())
{
throw new ContextNotActiveException("WebBeans context with scope annotation " +
"@ViewScoped is not active with respect to the current thread");
}
}
/**
* {@inheritDoc}
*/
public boolean isListenerForSource(Object source)
{
if (source instanceof UIViewRoot)
{
return true;
}
return false;
}
/**
* We get PreDestroyViewMapEvent events from the JSF servlet and destroy our contextual
* instances. This should (theoretically!) also get fired if the webapp closes, so there
* should be no need to manually track all view scopes and destroy them at a shutdown.
*
* @see javax.faces.event.SystemEventListener#processEvent(javax.faces.event.SystemEvent)
*/
@SuppressWarnings(UNCHECKED)
public void processEvent(SystemEvent event)
{
if (event instanceof PreDestroyViewMapEvent)
{
// better use the viewmap we get from the event to prevent concurrent modification problems
Map<String, Object> viewMap = ((UIViewRoot) event.getSource()).getViewMap();
Map<String, Object> componentIdMap
= (Map<String, Object>) viewMap.get(COMPONENT_ID_MAP_NAME);
Map<String, CreationalContext<?>> creationalContextMap
= (Map<String, CreationalContext<?>>) viewMap.get(CREATIONAL_MAP_NAME);
if(componentIdMap != null)
{
BeanManager beanManager = BeanManagerProvider.getInstance().getBeanManager();
for ( Entry<String, Object> componentEntry : componentIdMap.entrySet())
{
String beanId = componentEntry.getKey();
// there is no nice way to explain the Java Compiler that we are handling the same type T,
// therefore we need completely drop the type information :(
Contextual contextual = beanManager.getPassivationCapableBean(beanId);
Object instance = componentEntry.getValue();
CreationalContext creational = creationalContextMap.get(beanId);
contextual.destroy(instance, creational);
}
}
}
}
protected UIViewRoot getViewRoot()
{
FacesContext context = FacesContext.getCurrentInstance();
if(context != null)
{
return context.getViewRoot();
}
return null;
}
protected Map<String, Object> getViewMap()
{
UIViewRoot viewRoot = getViewRoot();
if (viewRoot != null)
{
return viewRoot.getViewMap(true);
}
return null;
}
}