Remoting.IO

Simple and transparent remote procedure calls (RPC) using Engine.IO.

The client repository is located here.

About

Remoting.IO allows services to export methods remotely. Services are simply plain prototypical Javascript classes which define a number of methods that can be called remotely.

Because Engine.IO is connection oriented, services are stateful. This means session data can be persisted across services and method invocations. Remoting.IO provides a session hash map that is injected into instances of services for exactly this purpose.

Remoting.IO is able to handle both synchronous and asynchronous methods. The only constraint is that asynchronous methods must return an ES6 promise.

Because Remoting.IO is based on Engine.IO, it inherits the strengths of Engine.IO, such as multiple transports and resilience in the presence of proxies, load balancers, and firewalls.

Installation

Install Engine.IO and Remoting.IO with:

npm install engine.io
npm install remoting.io

Server Example

Define a service as follows:

function TestService(arg1, arg2) {
	this.arg1 = arg1;
	this.session['arg2'] = arg2;
}

TestService.prototype.test1 = function (str1, str2) {
	return str1 + str2;
};

TestService.prototype.test2 = function () {
	var self = this;

	return new Promise(function (resolve) {
		resolve(self.arg1 + self.session['arg2']);
	});
};

TestService.exports = [ 'test1', 'test2' ];

Setup the RPC server as follows:

var engine = require('engine.io');
var remoting = require('remoting.io');

var socketServer = engine.listen(80);
var rpcServer = remoting(socketServer);

rpcServer.addService('TestService', TestService, ['Hello', 'World!']);
rpcServer.start();

When a client connects and requests an instance of TestService, 'Hello' and 'World!' will be passed into arg1 and arg2 of the service constructor respectively.

Client Example

Using the server example above, we can remotely request an instance of the service and call it's method as follows:

var socket = eio('ws://localhost');
var client = rio(socket);
	
client.proxy('TestService').then(function (testService) {
	testService.test1('Hello', 'World!').then(function (result) {
		console.log(result);
		testService.release();
	});	
});

This example assumes that engine.io.js and remoting.io.js have been loaded into the DOM.

Using Browserify:

var socket = require('engine.io-client')('ws://localhost');
var client = require('remoting.io-client')(socket);
	
client.proxy('TestService').then(function (testService) {
	testService.test1('Hello', 'World!').then(function (result) {
		console.log(result);
		testService.release();
	});	
});

API

Server

• constructor

  • Initializes the server
  • Parameters:
    • socketServer: an Engine.IO (or equivalent) server instance

• start

  • Starts the RPC server

• stop

  • Stops the RPC server

• addService

  • Registers an RPC service
  • Parameters:
    • name: The service identifier
    • service: The service class
    • args: Arguments that are passed to the service constructor when a new instance of the service is created

• removeService

  • Unregisters an RPC service
  • Parameters:
    • name: The service identifier

Head over to the Remoting.IO client repository for instructions on how to use the client.

License

Copyright (c) 2015 James McLean
Licensed under the MIT license.