moleculer/src/transporters/base.js

Fast & powerful microservices framework for Node.JS

/*
 * moleculer
 * Copyright (c) 2017 Ice Services (https://github.com/ice-services/moleculer)
 * MIT Licensed
 */


"use strict";

// Prefix for logger
const LOG_PREFIX = "TX";

/**
 * Base Transporter class
 * 
 * @class BaseTransporter
 */
class BaseTransporter {

	/**
	 * Creates an instance of BaseTransporter.
	 * 
	 * @param {any} opts
	 * 
	 * @memberOf BaseTransporter
	 */
	constructor(opts) {
		this.opts = opts || {};
		this.connected = false;

		this.prefix = "MOL";
		
		if (this.opts.prefix) {
			this.prefix = this.opts.prefix;
		}
	}

	/**
	 * Init transporter
	 * 
	 * @param {Transit} transit
	 * @param {Function} messageHandler
	 * @param {Function} afterConnect
	 * 
	 * @memberOf BaseTransporter
	 */
	init(transit, messageHandler, afterConnect) {
		if (transit) {
			this.transit = transit;
			this.broker = transit.broker;
			this.nodeID = transit.nodeID;
			this.logger = this.broker.getLogger(LOG_PREFIX);
		}
		this.messageHandler = messageHandler;
		this.afterConnect = afterConnect;
	}

	/**
	 * Connect to the transporter server
	 * 
	 * @memberOf BaseTransporter
	 */
	connect() {
		/* istanbul ignore next */
		throw new Error("Not implemented!");
	}

	/**
	 * Event handler for connected.
	 * 
	 * @param {any} wasReconnect 
	 * @returns {Promise}
	 * 
	 * @memberof BaseTransporter
	 */
	onConnected(wasReconnect) {
		this.connected = true;
		if (this.afterConnect) {
			return this.afterConnect(wasReconnect);
		}

		return Promise.resolve();
	}

	/**
	 * Disconnect from the transporter server
	 * 
	 * @memberOf BaseTransporter
	 */
	disconnect() {
		/* istanbul ignore next */
		throw new Error("Not implemented!");
	}

	/**
	 * Subscribe to a command
	 * 
	 * @param {String} cmd 
	 * @param {String} nodeID 
	 * 
	 * @memberOf BaseTransporter
	 */
	subscribe(/*cmd, nodeID*/) {
		/* istanbul ignore next */
		throw new Error("Not implemented!");
	}

	/**
	 * Publish a packet
	 * 
	 * @param {Packet} packet
	 * 
	 * @memberOf BaseTransporter
	 */
	publish(/*packet*/) {
		/* istanbul ignore next */
		throw new Error("Not implemented!");
	}

	/**
	 * Get topic name from command & target nodeID
	 * 
	 * @param {any} cmd 
	 * @param {any} nodeID 
	 * 
	 * @memberOf BaseTransporter
	 */
	getTopicName(cmd, nodeID) {
		return this.prefix + "." + cmd + (nodeID ? "." + nodeID : "");
	}

}

module.exports = BaseTransporter;