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/*
* Copyright (c) 1997, 2020 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 jakarta.faces.component;
import jakarta.faces.context.FacesContext;
/**
*
*
* This interface is implemented by classes that need to save their
* state between requests.
*
*
*
* An implementor must implement both {@link #saveState} and {@link #restoreState} methods in this
* class, since these two methods have a tightly coupled contract between themselves. In other words, if there is an
* ineritance hierarchy, it is not permissable to have the {@link #saveState} and {@link #restoreState} methods reside
* at different levels of the hierarchy.
*
*
*
* An implementor must have a public no-args constructor.
*
*
*/
public interface StateHolder {
/**
*
* Gets the state of the instance as a Serializable Object.
*
*
*
* If the class that implements this interface has references to instances that implement StateHolder (such as a
* UIComponent with event handlers, validators, etc.) this method must call the {@link #saveState} method
* on all those instances as well. This method must not save the state of children and facets. That is
* done via the {@link jakarta.faces.application.StateManager}
*
*
*
* This method must not alter the state of the implementing object. In other words, after executing this code:
*
*
*
*
* Object state = component.saveState(facesContext);
*
*
*
*
* component should be the same as before executing it.
*
*
*
* The return from this method must be Serializable
*
*
* @param context the Faces context.
* @return the saved state.
* @throws NullPointerException if context is null
*/
Object saveState(FacesContext context);
/**
*
*
* Perform any processing required to restore the state from the entries
* in the state Object.
*
*
*
* If the class that implements this interface has references to instances that also implement StateHolder (such as a
* UIComponent with event handlers, validators, etc.) this method must call the {@link #restoreState}
* method on all those instances as well.
*
*
*
* If the state argument is null, take no action and return.
*
*
* @param context the Faces context.
* @param state the state.
* @throws NullPointerException if context is null.
*/
void restoreState(FacesContext context, Object state);
/**
*
*
* If true, the Object implementing this interface must not participate in state saving or restoring.
*
*
* @return true if transient, false otherwise.
*/
boolean isTransient();
/**
*
* Denotes whether or not the Object implementing this interface must or
* must not participate in state saving or restoring.
*
*
* @param newTransientValue boolean pass true if this Object will
* not participate in state saving or restoring, otherwise pass false.
*/
void setTransient(boolean newTransientValue);
}