Files
kami-parse-server/src/LiveQuery/EventEmitterPubSub.js
wangmengyan95 555e25bf33 Add LiveQuery
2016-03-18 12:32:31 -07:00

60 lines
1.1 KiB
JavaScript

import events from 'events';
let emitter = new events.EventEmitter();
class Publisher {
emitter: any;
constructor(emitter: any) {
this.emitter = emitter;
}
publish(channel: string, message: string): void {
this.emitter.emit(channel, message);
}
}
class Subscriber extends events.EventEmitter {
emitter: any;
subscriptions: any;
constructor(emitter: any) {
super();
this.emitter = emitter;
this.subscriptions = new Map();
}
subscribe(channel: string): void {
let handler = (message) => {
this.emit('message', channel, message);
}
this.subscriptions.set(channel, handler);
this.emitter.on(channel, handler);
}
unsubscribe(channel: string): void {
if (!this.subscriptions.has(channel)) {
return;
}
this.emitter.removeListener(channel, this.subscriptions.get(channel));
this.subscriptions.delete(channel);
}
}
function createPublisher(): any {
return new Publisher(emitter);
}
function createSubscriber(): any {
return new Subscriber(emitter);
}
let EventEmitterPubSub = {
createPublisher,
createSubscriber
}
export {
EventEmitterPubSub
}