001/*
002 * JGrapes Event Driven Framework
003 * Copyright (C) 2017-2018 Michael N. Lipp
004 * 
005 * This program is free software; you can redistribute it and/or modify it 
006 * under the terms of the GNU Affero General Public License as published by 
007 * the Free Software Foundation; either version 3 of the License, or 
008 * (at your option) any later version.
009 * 
010 * This program is distributed in the hope that it will be useful, but 
011 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
012 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License 
013 * for more details.
014 * 
015 * You should have received a copy of the GNU Affero General Public License along 
016 * with this program; if not, see <http://www.gnu.org/licenses/>.
017 */
018
019package org.jgrapes.webconsole.base.events;
020
021import org.jgrapes.core.Associator;
022import org.jgrapes.core.Event;
023
024/**
025 * A notification within the server side that an item that is expected 
026 * to be associated with a channel is missing or not in a usable state. 
027 * The item specification is usually the key used by the {@link Associator}. 
028 * 
029 * This event may be fired by components that require the item and 
030 * should be handled by the component that is responsible for 
031 * providing the item.
032 * 
033 * @see ResourceUpdated
034 */
035public class ResourceNotAvailable extends Event<Void> {
036
037    private final Object itemSpecification;
038
039    /**
040     * Creates a new event.
041     *
042     * @param itemSpecification information about the item, usually the 
043     * item's class.
044     */
045    public ResourceNotAvailable(Object itemSpecification) {
046        this.itemSpecification = itemSpecification;
047    }
048
049    /**
050     * Return the information that specifies the item. 
051     *
052     * @return the item specification
053     */
054    public Object itemSpecification() {
055        return itemSpecification;
056    }
057}