IEventManager.java

/*
 * #%L
 * carewebframework
 * %%
 * Copyright (C) 2008 - 2016 Regenstrief Institute, Inc.
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * This Source Code Form is also subject to the terms of the Health-Related
 * Additional Disclaimer of Warranty and Limitation of Liability available at
 *
 *      http://www.carewebframework.org/licensing/disclaimer.
 *
 * #L%
 */
package org.carewebframework.api.event;

import org.carewebframework.api.messaging.Recipient;

/**
 * Defines the interface for accessing event management services.
 */
public interface IEventManager {
    
    /**
     * Returns true if the specified event has any local subscribers.
     * 
     * @param eventName Name of the event.
     * @return True if the event has subscribers. Includes subscribers to any parent events.
     */
    boolean hasSubscribers(String eventName);
    
    /**
     * Returns true if the specified event has any local subscribers.
     * 
     * @param eventName Name of the event.
     * @param exact If true, do not consider subscribers to parent events.
     * @return True if the event has subscribers.
     */
    boolean hasSubscribers(String eventName, boolean exact);
    
    /**
     * Fires the specified event locally.
     * 
     * @param eventName Name of the event to fire.
     * @param eventData Associated data object.
     */
    void fireLocalEvent(String eventName, Object eventData);
    
    /**
     * Fires the event remotely via the global event manager.
     * 
     * @param eventName Name of the event to fire.
     * @param eventData Associated data object.
     * @param recipients Optional list of event recipients.
     */
    void fireRemoteEvent(String eventName, Object eventData, Recipient... recipients);
    
    /**
     * Register an event subscription.
     * 
     * @param eventName Name of event.
     * @param subscriber Subscriber to event.
     */
    void subscribe(String eventName, IGenericEvent<?> subscriber);
    
    /**
     * Unregister an event subscription. If the subscriber has no existing subscription then this
     * call has no effect.
     * 
     * @param eventName Name of event.
     * @param subscriber Subscriber to event.
     */
    void unsubscribe(String eventName, IGenericEvent<?> subscriber);
    
}