javax.faces.view.StateManagementStrategy Maven / Gradle / Ivy
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* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package javax.faces.view;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
/**
* Encapsulate the saving and
* restoring of the view to enable the VDL to take over the
* responsibility for handling this feature. Because {@link
* ViewDeclarationLanguage#getStateManagementStrategy} is required to
* return null for JSP views and non-null for
* views authored in Facelets for JSF 2, this specification only applys
* to Facelets for JSF 2.
*
* Implementations must call
* {@link javax.faces.component.UIComponent#visitTree} on the
* {@link javax.faces.component.UIViewRoot} to perform the saving and restoring
* of the view in the {@link #saveView} and {@link #restoreView} methods,
* respectively.
*
*
* @since 2.0
*/
public abstract class StateManagementStrategy {
/**
* 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 {@link
javax.faces.component.UIComponent#visitTree}. For each node,
call {@link javax.faces.component.UIComponent#saveState},
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 {@link
* javax.faces.component.UIComponent#saveState} 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.
*
* @param context the FacesContext for this request.
*
* @since 2.0
*
* @return the saved view state
*/
public abstract Object saveView(FacesContext context);
/**
* 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 {@link ViewMetadata} for
the current viewId, and from that call {@link
ViewMetadata#createMetadataView}. Store the resultant {@link
UIViewRoot} in the {@link FacesContext}. Obtain the state of
the UIViewRoot from the state Object
returned from {@link
javax.faces.render.ResponseStateManager#getState} and pass
that to {@link UIViewRoot#restoreViewScopeState}.
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 {@link
javax.faces.render.ResponseStateManager#getState} to obtain
the data structure returned from the previous call to {@link
#saveView}.
Visit the tree using {@link
javax.faces.component.UIComponent#visitTree}. For each node,
call {@link javax.faces.component.UIComponent#restoreState},
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 {@link
* javax.faces.component.UIComponent#restoreState} method is called
* for each node in the tree, except for those that were
* programmatically deleted on the previous run through the
* lifecycle.
*
*
* @param context the FacesContext for this request
* @param viewId the view identifier for which the state should be restored
* @param renderKitId the render kit id for this state.
* @since 2.0
*
* @return the root of the restored view
*/
public abstract UIViewRoot restoreView(FacesContext context, String viewId,
String renderKitId);
}