/*
* Copyright 2004 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.
*
* $Header:$
*/
package org.apache.beehive.netui.pageflow;
import org.apache.beehive.netui.pageflow.internal.InternalConstants;
import org.apache.beehive.netui.pageflow.internal.InternalUtils;
import org.apache.beehive.netui.pageflow.internal.CachedFacesBackingInfo;
import org.apache.beehive.netui.pageflow.internal.AdapterManager;
import org.apache.beehive.netui.pageflow.internal.CachedSharedFlowRefInfo;
import org.apache.beehive.netui.pageflow.scoping.ScopedServletUtils;
import org.apache.beehive.netui.util.internal.cache.ClassLevelCache;
import org.apache.beehive.netui.util.logging.Logger;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletContext;
import java.util.Map;
import java.util.Collections;
import java.lang.reflect.Field;
/**
* <p>
* A JavaServer Faces backing bean. An instance of this class will be created whenever a corresponding JSF path is
* requested (e.g., an instance of foo.MyPage will be created for the webapp-relative path "/foo/MyPage.faces"). The
* instance will be released (removed from the user session) when a non-matching path is requested. A faces backing
* bean can hold component references and event/command handlers, and it can raise actions with normal JSF command event
* handlers that are annotated with {@link org.apache.beehive.netui.pageflow.annotations.Jpf.CommandHandler @Jpf.CommandHandler}.
* The bean instance can be bound to with a JSF-style expression like <code>#{backing.myComponent}</code>.
* </p>
* <p>
* JSF backing beans are configured using the
* {@link org.apache.beehive.netui.pageflow.annotations.Jpf.FacesBacking @Jpf.FacesBacking} annotation.
* </p>
*/
public abstract class FacesBackingBean
extends PageFlowManagedObject
{
private static final String CACHED_INFO_KEY = "cachedInfo";
private static final Logger _log = Logger.getInstance( FacesBackingBean.class );
private Map _pageInputs;
/**
* Store this object in the user session, in the appropriate place. Used by the framework; normally should not be
* called directly.
*/
public void persistInSession( HttpServletRequest request, HttpServletResponse response )
{
HttpServletRequest unwrappedRequest = PageFlowUtils.unwrapMultipart( request );
ScopedServletUtils.setScopedSessionAttr( InternalConstants.FACES_BACKING_ATTR, this, unwrappedRequest );
}
/**
* Remove this instance from the session.
*/
protected void removeFromSession( HttpServletRequest request )
{
HttpServletRequest unwrappedRequest = PageFlowUtils.unwrapMultipart( request );
ScopedServletUtils.removeScopedSessionAttr( InternalConstants.FACES_BACKING_ATTR, unwrappedRequest );
}
/**
* Ensures that any changes to this object will be replicated in a cluster (for failover),
* even if the replication scheme uses a change-detection algorithm that relies on
* HttpSession.setAttribute to be aware of changes. Note that this method is used by the framework
* and does not need to be called explicitly in most cases.
*
* @param request the current HttpServletRequest
*/
public void ensureFailover( HttpServletRequest request )
{
HttpServletRequest unwrappedRequest = PageFlowUtils.unwrapMultipart( request );
String attr =
ScopedServletUtils.getScopedSessionAttrName( InternalConstants.FACES_BACKING_ATTR, unwrappedRequest );
ServletContext servletContext = InternalUtils.getServletContext( request );
AdapterManager.getServletContainerAdapter( servletContext ).ensureFailover( attr, this, unwrappedRequest );
}
/**
* Get the display name for the bean. For FacesBackingBeans, this is simply the class name.
*/
public String getDisplayName()
{
return getClass().getName();
}
/**
* Reinitialize the bean for a new request. Used by the framework; normally should not be called directly.
*/
public void reinitialize( HttpServletRequest request, HttpServletResponse response, ServletContext servletContext )
{
super.reinitialize( request, response, servletContext );
if ( _pageInputs == null )
{
Map map = InternalUtils.getActionOutputMap( request, false );
if ( map != null ) _pageInputs = Collections.unmodifiableMap( map );
}
//
// Initialize the page flow field.
//
Field pageFlowMemberField = getCachedInfo().getPageFlowMemberField();
// TODO: should we add a compiler warning if this field isn't transient? All this reinitialization logic is
// for the transient case.
if ( fieldIsUninitialized( pageFlowMemberField ) )
{
PageFlowController pfc = PageFlowUtils.getCurrentPageFlow( request );
initializeField( pageFlowMemberField, pfc );
}
//
// Initialize the shared flow fields.
//
CachedSharedFlowRefInfo.SharedFlowFieldInfo[] sharedFlowMemberFields =
getCachedInfo().getSharedFlowMemberFields();
if ( sharedFlowMemberFields != null )
{
for ( int i = 0; i < sharedFlowMemberFields.length; i++ )
{
CachedSharedFlowRefInfo.SharedFlowFieldInfo fi = sharedFlowMemberFields[i];
Field field = fi.field;
if ( fieldIsUninitialized( field ) )
{
Map/*< String, SharedFlowController >*/ sharedFlows = PageFlowUtils.getSharedFlows( request );
String name = fi.sharedFlowName;
SharedFlowController sf =
name != null ? ( SharedFlowController ) sharedFlows.get( name ) : PageFlowUtils.getGlobalApp( request );
if ( sf != null )
{
initializeField( field, sf );
}
else
{
_log.error( "Could not find shared flow with name \"" + fi.sharedFlowName
+ "\" to initialize field " + field.getName() + " in " + getClass().getName() );
}
}
}
}
}
/**
* Get a page input that was passed from a Page Flow action as an "action output".
*
* @param pageInputName the name of the page input. This is the same as the name of the "action output".
* @return the value of the page input, or <code>null</code> if the given one does not exist.
*/
protected Object getPageInput( String pageInputName )
{
return _pageInputs != null ? _pageInputs.get( pageInputName ) : null;
}
/**
* Get the map of all page inputs that was passed from a Page Flow action as "action outputs".
*
* @return a Map of page-input-name (String) to page-input-value (Object).
*/
public Map getPageInputMap()
{
return _pageInputs;
}
private CachedFacesBackingInfo getCachedInfo()
{
ClassLevelCache cache = ClassLevelCache.getCache( getClass() );
CachedFacesBackingInfo info = ( CachedFacesBackingInfo ) cache.getCacheObject( CACHED_INFO_KEY );
if ( info == null )
{
info = new CachedFacesBackingInfo( getClass(), getServletContext() );
cache.setCacheObject( CACHED_INFO_KEY, info );
}
return info;
}
}