org.omnifaces.taghandler

Class EnableRestorableView

java.lang.Object

javax.faces.view.facelets.TagHandler

org.omnifaces.taghandler.EnableRestorableView

All Implemented Interfaces:

javax.faces.view.facelets.FaceletHandler

public class EnableRestorableView
extends javax.faces.view.facelets.TagHandler

The <o:enableRestorableView> instructs the view handler to recreate the entire view whenever the view has been expired, i.e. whenever ViewHandler.restoreView(FacesContext, String) returns null and the current request is a postback. This effectively prevents ViewExpiredException on the view. This tag needs to be placed in <f:metadata> of the view.

There are however technical design limitations: the recreated view is exactly the same as during the initial request, so any modifications which are made thereafter, either by taghandlers or conditionally rendered components based on some view or even session scoped variables, are completely lost. In order to recreate exactly the desired view, you would need to make sure that those modifications are made based on request scoped variables (read: request parameters) instead of view or session scoped variables. In other words, the state of the restorable view should not depend on view or session scoped managed beans, but purely on request scoped managed beans.

To enable the restorable view, just add the <enableRestorableView> to the view metadata.

 <f:metadata>
   <o:enableRestorableView/>
 </f:metadata>
 

Since:

1.3

Author:

Bauke Scholtz

See Also:

RestorableViewHandler

Field Summary

Fields inherited from class javax.faces.view.facelets.TagHandler

nextHandler, tag, tagId

Constructor Summary

Constructors

Constructor and Description
EnableRestorableView(javax.faces.view.facelets.TagConfig config) The tag constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	apply(javax.faces.view.facelets.FaceletContext context, javax.faces.component.UIComponent parent) Enable the current view to be restorable.

Methods inherited from class javax.faces.view.facelets.TagHandler

getAttribute, getRequiredAttribute, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

EnableRestorableView

public EnableRestorableView(javax.faces.view.facelets.TagConfig config)

The tag constructor.

Parameters:

config - The tag config.

Method Detail

apply

public void apply(javax.faces.view.facelets.FaceletContext context,
         javax.faces.component.UIComponent parent)
           throws java.io.IOException

Enable the current view to be restorable. This basically sets a specific view attribute which the RestorableViewHandler could intercept on.

Throws:

java.lang.IllegalArgumentException - When given parent is not an instance of UIViewRoot.

java.io.IOException