public abstract class StateManagementStrategy
extends java.lang.Object
Encapsulate the saving and
restoring of the view to enable the VDL to take over the
responsibility for handling this feature. Because ViewDeclarationLanguage.getStateManagementStrategy(javax.faces.context.FacesContext, java.lang.String) is required to
return null for Jakarta Server Pages views and non-null for
views authored in Facelets for Jakarta Server Faces 2, this specification only applies
to Facelets for Jakarta Server Faces 2.
Implementations must call
UIComponent.visitTree(javax.faces.component.visit.VisitContext, javax.faces.component.visit.VisitCallback) on the
UIViewRoot to perform the saving and restoring
of the view in the saveView(javax.faces.context.FacesContext) and restoreView(javax.faces.context.FacesContext, java.lang.String, java.lang.String) methods,
respectively.
| Constructor and Description |
|---|
StateManagementStrategy() |
| Modifier and Type | Method and Description |
|---|---|
abstract UIViewRoot |
restoreView(FacesContext context,
java.lang.String viewId,
java.lang.String renderKitId)
Restore the state of the view with information in the request. |
abstract java.lang.Object |
saveView(FacesContext context)
Return the state of the
current view in an |
public abstract java.lang.Object saveView(FacesContext context)
Return the state of the
current view in an Object that implements
Serializable and
can be passed to
java.io.ObjectOutputStream.writeObject() without
causing a java.io.NotSerializableException to be
thrown. The default implementation must perform the
following algorithm or its semantic equivalent, explicitly performing all the steps
listed here.
If the UIViewRoot of the current view is
marked transient, return null
immediately.
Traverse the view and verify that each of the client ids
are unique. Throw IllegalStateException if more
than one client id are the same.
Visit the tree using UIComponent.visitTree(javax.faces.component.visit.VisitContext, javax.faces.component.visit.VisitCallback). For each node,
call StateHolder.saveState(javax.faces.context.FacesContext),
saving the returned Object in a way such that it
can be restored given only its client id. Special care must
be taken to handle the case of components that were added or
deleted programmatically during this lifecycle traversal,
rather than by the VDL.
The implementation must ensure that the StateHolder.saveState(javax.faces.context.FacesContext) method is called for
each node in the tree.
The data structure used to save the state obtained by
executing the above algorithm must be Serializable,
and all of the elements within the data structure must also be
Serializable.
context - the FacesContext for this request.public abstract UIViewRoot restoreView(FacesContext context, java.lang.String viewId, java.lang.String renderKitId)
Restore the state of the view with information in the request. The default implementation must perform the following algorithm or its semantic equivalent.
As in the case of restore view on
an initial request, the view metadata must be restored and
properly handled as well. Obtain the ViewMetadata for
the current viewId, and from that call ViewMetadata.createMetadataView(javax.faces.context.FacesContext). Store the resultant UIViewRoot in the FacesContext. Obtain the state of
the UIViewRoot from the state Object
returned from ResponseStateManager.getState(javax.faces.context.FacesContext, java.lang.String) and pass
that to UIViewRoot.restoreViewScopeState(javax.faces.context.FacesContext, java.lang.Object).
Build the view from the markup. For all components in the view that do not have an explicitly assigned id in the markup, the values of those ids must be the same as on an initial request for this view. This view will not contain any components programmatically added during the previous lifecycle run, and it will contain components that were programmatically deleted on the previous lifecycle run. Both of these cases must be handled.
Call ResponseStateManager.getState(javax.faces.context.FacesContext, java.lang.String) to obtain
the data structure returned from the previous call to saveView(javax.faces.context.FacesContext).
Visit the tree using UIComponent.visitTree(javax.faces.component.visit.VisitContext, javax.faces.component.visit.VisitCallback). For each node,
call StateHolder.restoreState(javax.faces.context.FacesContext, java.lang.Object),
passing the state saved corresponding to the current client
id.
Ensure that any programmatically deleted components are removed.
Ensure any programmatically added components are added.
The implementation must ensure that the StateHolder.restoreState(javax.faces.context.FacesContext, java.lang.Object) method is called
for each node in the tree, except for those that were
programmatically deleted on the previous run through the
lifecycle.
context - the FacesContext for this requestviewId - the view identifier for which the state should be restoredrenderKitId - the render kit id for this state.