/*
* Copyright 2013-2014 the original author or authors.
*
* 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.
*/
package net.kuujo.vertigo.hook;
import net.kuujo.vertigo.component.Component;
import net.kuujo.vertigo.component.InstanceContext;
import net.kuujo.vertigo.util.Contexts;
import org.vertx.java.core.eventbus.EventBus;
import org.vertx.java.core.json.JsonObject;
import com.fasterxml.jackson.annotation.JsonIgnore;
/**
* Event bus based hook implementation.<p>
*
* This hook publishes events to the event bus. Messages are published to the
* given address. If no address is provided then messages will be published
* to the internal address of the component to which the hook is attached.<p>
*
* Messages are formatted as {@link JsonObject} instances. Each message will have
* an <code>event</code> key which indicates the event that occurred. Additional
* keys depend on the event.<p>
*
* You can use an {@link EventBusHookListener} to listen for messages from an
* <code>EventBusHook</code>. This listener will handle parsing messages and
* calling event handlers.
*
* @author <a href="http://github.com/kuujo">Jordan Halterman</a>
*/
public class EventBusHook implements ComponentHook {
@JsonIgnore private InstanceContext context;
@JsonIgnore private EventBus eventBus;
private String address;
public EventBusHook() {
}
public EventBusHook(String address) {
this.address = address;
}
@Override
public void handleStart(Component component) {
this.eventBus = component.vertx().eventBus();
this.context = component.context();
if (this.address == null) {
this.address = component.context().component().address();
}
eventBus.publish(address, new JsonObject().putString("event", "start").putObject("context", Contexts.serialize(context)));
}
@Override
public void handleSend(Object message) {
eventBus.publish(address, new JsonObject().putString("event", "send").putValue("message", message));
}
@Override
public void handleReceive(Object message) {
eventBus.publish(address, new JsonObject().putString("event", "receive").putValue("message", message));
}
@Override
public void handleStop(Component subject) {
eventBus.publish(address, new JsonObject().putString("event", "stop").putObject("context", Contexts.serialize(context)));
}
}