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/*
* 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.custom.savestate;
import javax.faces.component.StateHolder;
import javax.faces.component.UIParameter;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
/**
* Provides the ability to store a model value inside the view's component tree.
*
* JSF provides three scopes for managed beans and therefore all the model
* objects that the managed beans reference: request, session, application.
* However a common requirement is a way for a model object to have a scope
* that is tied to the duration of the current view; that is longer than the
* request scope but shorter than session scope.
*
* This component simply holds a reference to an arbitrary object (specified
* by the value property). Because this object is an ordinary component whose
* scope is the current view, the reference to the model automatically has that
* same scope.
*
* When the value is an EL expression, then after the view is restored the
* recreated target object is stored at the specified location.
*
* The object being saved must either:
*
* - implement java.io.Serializable, or
*
- implement javax.faces.component.StateHolder and have a default
* constructor.
*
*
* Note that the saved object can be "chained" from view to view
* in order to extend its lifetime from a single view to a sequence
* of views if desired. A UISaveState component with an EL expression
* such as "#{someBean}" will save the object state after render, and
* restore it on postback. If navigation occurs to some other view
* and that view has a UISaveState component with the same EL expression
* then the object will simply be saved into the new view, thus extending
* its lifetime.
*
* @author Manfred Geiler (latest modification by $Author: paulsp $)
* @version $Revision: 491777 $ $Date: 2007-01-02 12:27:11 +0100 (Di, 02 Jän 2007) $
*/
public class UISaveState
extends UIParameter
{
public Object saveState(FacesContext context)
{
Object values[] = new Object[3];
values[0] = super.saveState(context);
Object objectToSave = getValue();
if (objectToSave instanceof StateHolder)
{
values[1] = Boolean.TRUE;
values[2] = saveAttachedState(context, objectToSave);
}
else
{
values[1] = Boolean.FALSE;
values[2] = objectToSave;
}
return values;
}
public void restoreState(FacesContext context, Object state)
{
Object values[] = (Object[])state;
super.restoreState(context, values[0]);
Object savedObject;
Boolean storedObjectIsAStateHolder = (Boolean) values[1];
if ( Boolean.TRUE.equals( storedObjectIsAStateHolder ) )
{
savedObject = restoreAttachedState(context,values[2]);
}
else
{
savedObject = values[2];
}
ValueBinding vb = getValueBinding("value");
if (vb != null)
{
vb.setValue(context, savedObject);
}
}
//------------------ GENERATED CODE BEGIN (do not modify!) --------------------
public static final String COMPONENT_TYPE = "org.apache.myfaces.SaveState";
public static final String COMPONENT_FAMILY = "javax.faces.Parameter";
public UISaveState()
{
}
public String getFamily()
{
return COMPONENT_FAMILY;
}
//------------------ GENERATED CODE END ---------------------------------------
}