    001// Copyright 2006, 2007, 2012 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.commons.services;
    016
    017/**
    018 * Interface for objects that may cache information that can be invalidated. Invalidation occurs when external files,
    019 * from which in-memory data is cached, is determined to have changed. Granularity is very limited; when any external
    020 * file is found to have changed, the event is fired (with the expectation that the cleared cache will be repopulated as
    021 * necessary).
    022 *
    023 * @see org.apache.tapestry5.commons.services.InvalidationEventHub
    024 * @since 5.1.0.0
    025 * @deprecated In 5.4; use {@link InvalidationEventHub#addInvalidationCallback(Runnable)} instead
    026 */
    027public interface InvalidationListener
    028{
    029    /**
    030     * Invoked to indicate that some object is invalid. The receiver should clear its cache.
    031     */
    032    void objectWasInvalidated();
    033}