001// Copyright 2006 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5;
016
017import java.io.Serializable;
018
019/**
020 * An action that is associated with a component. This is used in several areas of Tapestry and is primarily an attempt
021 * to externalize state for a component so that it can be recorded outside the object.
022 * <p/>
023 * ComponentActions should be immutable. They are often created during one request and associated with a particular
024 * component instance. They are then used in a later request (with an equivalent component instance).
025 * <p/>
026 * ComponentActions are serializable (they are often serialized into Base64 strings for storage on the client).
027 */
028public interface ComponentAction<T> extends Serializable
029{
030    /**
031     * Passed a component instance, the action should operate upon the instance.
032     */
033    void execute(T component);
034}