Your browser doesn't support the features required by impress.js, so you are presented with a simplified version of this presentation.

For the best experience please use the latest Chrome or Safari browser. Firefox 10 (to be released soon) will also handle it.

RMI.js

Massimiliano Marcon (@mmarcon) - 07.02.12

Beyond the boundaries of the browser.

Summary

Demo Demo first? Quite unusual...

Follow @rmijs on Twitter...

Demo screenshot

I'll show the code at the end of the presentation.

What is RMI.js?

Think of Java Remote Method Invocation (RMI) in the Javascript world.

Java RMI was a good idea. Almost.

You can have a distributed system where clients can invoke methods that are implemented somewhere else.

The bad part is the overly complex way in which this can be accomplished: stub, skeleton, interfaces that have to extend java.rmi.Remote, naming lookup, policy files for permissions, etc. etc. etc.

RMI architecture

The idea behind RMI.js

is to reuse the good concepts behind Java RMI and make remote invocations simple and efficient by taking advantage of the flexibily and the peculiarities of Javascript.

Browser side Javascript +

Node.js +

Socket.io =

RMI.js

Why would I use RMI.js?

Because it makes your code Beautiful. And also more compact, semantic, less confusing and more maintainable.

Say we want to load a list of users from the backend:

            
$.ajax({
    url: 'http://coolwebapp.com/rest/users',
    success: function(data){
                 var list = $('ul.users');
                 $.each(data, function(user){
                     list.append($('<li>' + user.name + '</li>'));
                 });
             }
    });

vs 

            
RESTService.getUsers()
           .then(function(data){
                     var list = $('ul.users');
                     $.each(data, function(user){
                        list.append($('<li>' + user.name + '</li>'));
                     });
                 });

Oh, yeah, you get Promises too...

and one more
*important* thing...

by using Websockets (via Socket.io) we cut all the overhead of the HTTP protocol.

Less bytes over the wire and significant improvements in terms of latency.

RMI.js includes an additional supercool feature: Method Push

In the spirit of efficiency, the system can be set to push the implementation of a remote method to the client when such method starts being invoked very often.*

*This is still at a very early stage and the implementation is poor, but it works.

How Architecture & Implementation

On the client side

The developer creates sort-of-a-stub:

            
var SortOfAStub = {};
SortOfAStub.myRemoteMethod = function(){}; //Just a placeholder...
SortOfAStub.myRemoteMethod.remote = true;  //The method is remote

SortOfAStub.thisMethodIsNotRemoteInstead = function(){
    console.log('foo')}; //This method is local instead
                         //local and remote can be mixed
};

And then the magic happens...

            
RMIJS.Client(SortOfAStub).setEndpoint('http://server.com');

Behind the scenes the empty remote methods are replaced with a closure that when called triggers a remote invocation.

On the Node.js side

            
npm install rmi.js socket.io express

Environment setup + remote implementation:

            
var express = require('express'), app = express.createServer(),
    io = require('socket.io'), rmi = require('rmi.js'),
    socketio = io.listen(app);

rmi.handleRoutesFor(app); //So client-side and shared code are delivered
                          //to clients via express
rmi.ServerFactory.forImplementation({
    myRemoteMethod: function(){ //Remote implementation
        //Maybe do some stuff...
        return 'bar'
    }
});

socketio.sockets.on('connection', function(socket) {
    //when a connection is received
    //Socket.io passed it to RMI.js:
    //an instance of RMIJS.Server is returned
    var rmiServer = rmi.ServerFactory.getHandler(socket);
});

The code currently running in my browser...

Client code

...and what is running on the server.

Server code

Chat Status, Next steps, Q&A...

Thank you.

Use a spacebar or arrow keys to navigate