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.services;
014
015import java.util.Map;
016
017/**
018 * An object which manages a list of {@link org.apache.tapestry5.services.InvalidationListener}s. There are multiple
019 * event hub services implementing this interface, each with a specific marker annotation; each can register listeners
020 * and fire events; these are based on the type of resource that has been invalidated. Tapestry has built-in support
021 * for:
022 * <dl>
023 * <dt>message catalog resources
024 * <dd>{@link org.apache.tapestry5.services.ComponentMessages} marker annotation
025 * <dt>component templates
026 * <dd>{@link org.apache.tapestry5.services.ComponentTemplates} marker annotation
027 * <dt>component classes
028 * <dd>{@link org.apache.tapestry5.services.ComponentClasses} marker annotation
029 * </dl>
030 *
031 * Starting in Tapestry 5.3, these services are disabled in production (it does nothing).
032 *
033 * @since 5.1.0.0
034 */
035public interface InvalidationEventHub
036{
037    /**
038     * Adds a listener, who needs to know when an underlying resource of a given category has changed (so that the
039     * receiver may discard any cached data that may have been invalidated). Does nothing in production mode.
040     *
041     * @deprecated in 5.4, use {@link #addInvalidationCallback(Runnable)} instead}
042     */
043    void addInvalidationListener(InvalidationListener listener);
044
045    /**
046     * Adds a callback that is invoked when an underlying tracked resource has changed. Does nothing in production mode.
047     *
048     * @since  5.4
049     */
050    void addInvalidationCallback(Runnable callback);
051
052    /**
053     * Adds a callback that clears the map.
054     *
055     * @since 5.4
056     */
057    void clearOnInvalidation(Map<?,?> map);
058}