javax.faces.component.StateHelper 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.component;
import java.io.Serializable;
/**
* Define a Map-like contract
* that makes it easier for components to implement {@link
* PartialStateHolder}. Each {@link UIComponent} in the view will
* return an implementation of this interface from its {@link
* UIComponent#getStateHelper} method.
*
* @since 2.0
*/
public interface StateHelper extends StateHolder {
/**
* Return the previously stored value
* and store the specified key/value pair. This is intended to
* store data that would otherwise reside in an instance variable on
* the component.
*
* @param key the key for the value
* @param value the value
* @return the previously stored value
* @since 2.0
*/
Object put(Serializable key, Object value);
/**
* Remove the key/value pair from the
* helper, returning the value previously stored under this key.
*
* @param key the key to remove
* @return the removed value.
* @since 2.0
*/
Object remove(Serializable key);
/**
* Store the specified
* mapKey/value in a Map that
* is internal to the helper, and return the previously stored
* value. The Map will then be associated with
* key.
*
*
* It's important to note for delta tracking that any
* modifications to the internal Map be made through
* this method or {@link StateHelper#remove(java.io.Serializable,
* Object)}.
*
*
*
* @param key the key of the map itself
* @param mapKey the key within the internal map
* @param value the value for the key in the internal map
* @return the value.
* @since 2.0
*/
Object put(Serializable key, String mapKey, Object value);
/**
* Return the value currently
* associated with the specified key if any.
*
* @param key the key for which the value should be returned.
* @return the value.
* @since 2.0
*/
Object get(Serializable key);
/**
* Attempts to find a value associated
* with the specified key, using the value expression collection
* from the component if no such value is found.
*
* @param key the name of the value in the internal map, or the name
* of a value expression in the components value expression
* collection.
* @return the evaluated value.
* @since 2.0
*/
Object eval(Serializable key);
/**
* Performs the same logic as {@link
* #eval(java.io.Serializable)} } but if no value is found, this
* will return the specified defaultValue
* @param key the key for which the value should be returned.
* @param defaultValue the value to return if no value is found in
* the call to eval().
* @return the evaluated value.
* @since 2.0
*/
Object eval(Serializable key, Object defaultValue);
/**
* Store the specified
* value in a List that is internal to the
* StateHelper.
*
* It's important to note for delta
* tracking that any modifications to the internal List
* be made through this method or {@link
* StateHelper#remove(java.io.Serializable, Object)}.
*
* @param key the key for which the value should be returned.
* @param value the value to add
* @since 2.0
*/
void add(Serializable key, Object value);
/**
* Remove a value from the inner data
* structure. Look in the inner data structure for the value at the
* given key. If the value is a Map,
* remove and return the value under the key given by the
* valueOrKey argument. If the value is a
* Collection, simply remove the value given by
* the argument valueOrKey and return null.
*
* @param key the key of in the inner data structure whose value is
* a Collection or Map
* @param valueOrKey the value or key to be removed.
* @return the removed value.
*/
Object remove(Serializable key, Object valueOrKey);
}