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