Asymmetrik/node-rest-starter

import _ from 'lodash';
import { Socket } from 'socket.io';

import { BaseSocket, SocketConfig } from './base-socket.provider';
import { getEventEmitter } from '../event/event-emitter.service';

export default abstract class EventSocket extends BaseSocket {
    _emitterFunc;

    protected constructor(_socket: Socket, socketConfig: SocketConfig = {}) {
        super(_socket, socketConfig);
    }

    /**
     * Subscribe to an event.
     *
     * @return null if topic is not set, true if successful
     */
    subscribe(topic: string) {
        // Ignore bad input data
        if (null == topic) {
            return null;
        }

        // Simple throttling is done here, if enabled

        if (this._emitRateMs > 0) {
            this._emitterFunc = _.throttle(
                this.payloadHandler,
                this._emitRateMs
            ).bind(this, topic);
        } else {
            this._emitterFunc = this.payloadHandler.bind(this, topic);
        }
        getEventEmitter().on(topic, this._emitterFunc);
        return true;
    }

    /**
     * Unsubscribe from a topic.  If no topic is specified, unsubscribes from all topics consumed by this socket.
     *
     * @param {string} topic The topic to unsubscribe from (optional).
     */
    unsubscribe(topic: string) {
        if (typeof this._emitterFunc === 'function') {
            getEventEmitter().removeListener(topic, this._emitterFunc);
        }
    }
}