org.apache.myfaces.custom.savestate
Class UISaveState

java.lang.Object
  javax.faces.component.UIComponent
      javax.faces.component.UIComponentBase
          javax.faces.component.UIParameter
              org.apache.myfaces.custom.savestate.UISaveState

All Implemented Interfaces:

javax.faces.component.StateHolder

public class UISaveState
extends javax.faces.component.UIParameter

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.

Version:

$Revision: 673833 $ $Date: 2008-07-03 16:58:05 -0500 (Thu, 03 Jul 2008) $

Author:

Manfred Geiler (latest modification by $Author: skitching $)

Field Summary

static String	COMPONENT_FAMILY
static String	COMPONENT_TYPE

Constructor Summary

UISaveState()

Method Summary

String	getFamily()
void	restoreState(javax.faces.context.FacesContext context, Object state)
Object	saveState(javax.faces.context.FacesContext context)

Methods inherited from class javax.faces.component.UIParameter

getName, getValue, isRendered, setName, setRendered, setValue

Methods inherited from class javax.faces.component.UIComponentBase

addFacesListener, broadcast, decode, encodeBegin, encodeChildren, encodeEnd, findComponent, getAttributes, getChildCount, getChildren, getClientId, getFacesContext, getFacesListeners, getFacet, getFacets, getFacetsAndChildren, getId, getParent, getRenderer, getRendererType, getRendersChildren, getValueBinding, isTransient, processDecodes, processRestoreState, processSaveState, processUpdates, processValidators, queueEvent, removeFacesListener, restoreAttachedState, saveAttachedState, setId, setParent, setRendererType, setTransient, setValueBinding

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

COMPONENT_TYPE

public static final String COMPONENT_TYPE

See Also:

Constant Field Values

COMPONENT_FAMILY

public static final String COMPONENT_FAMILY

See Also:

Constant Field Values

Constructor Detail

UISaveState

public UISaveState()

Method Detail

saveState

public Object saveState(javax.faces.context.FacesContext context)

Specified by:

saveState in interface javax.faces.component.StateHolder

Overrides:

saveState in class javax.faces.component.UIParameter

restoreState

public void restoreState(javax.faces.context.FacesContext context,
                         Object state)

Specified by:

restoreState in interface javax.faces.component.StateHolder

Overrides:

restoreState in class javax.faces.component.UIParameter

getFamily

public String getFamily()

Overrides:

getFamily in class javax.faces.component.UIParameter