iowamp

WAMP™ server in NodeJS

npm install iowamp
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iowamp

iowamp is a WAMP™ server in NodeJS. Currently it only supports basic RPC calls, but pub/sub support is coming. It attaches to WebSocket.IO.

What is WAMP™?

WebSocket Application Messaging Protocol (WAMP) is a protocol for RPC & PubSub support, based on WebSockets. Technically, WAMP is an officially registered WebSocket subprotocol proposed by Tavendo.

License

Apache License (version 2)

Prerequisites

iowamp itselfs requires version 0.6.x of NodeJS or higher. If you want to run the tests, you'll want Vows. To really use iowamp, you will also need WebSocket.IO.

Installing with NPM

npm install iowamp

Attach iowamp to a websocket.io server

Before you can start using iowamp in your project, you need to attach it to an websocket.io instance of your choice:

var iowamp = require('./lib'),
    wsio = require('websocket.io');

var server = wsio.listen(8000);
var app = iowamp.attach(server);

Register a RPC class with methods

Registering a RPC class with some methods is also easy - here is an example for it:

var iowamp = require('./lib'),
    wsio = require('websocket.io');

var server = wsio.listen(8000);
var app = iowamp.attach(server);

app.rpc('http://example.com/calc#', function() {
    this.register('add', function(cb, a, b) {
        cb(null, a + b);
    });
});

The code should be kinda self-explanatory, allthough here is some additional information:

app.rpc(baseURI, constructor) registers a new RPC class

  • baseURI The base URI for the class. It must be a complete URI and it should end with a #. (A CURIE / compact URI is not allowed)
  • constructor Should be a function which registers some RPC methods (will get called in the iowamp scope)

this.register(name, method)

  • name The name of the method. To call the method in a WAMP client, you would need to specifiy the baseURI and the method name like here: http://example.com/calc#add
  • method The method which should be called. The first parameter is always the callback function, followed by the arguments passed from the WAMP client.

cb(error, result) Kinda self-explanatory. If an error will be passed, a generic error will be send back to the WAMP client. If not, the result will be send back.

Catching unknown methods

If you want to catch methods which are unknown / not declared, you can listen for the unknownCall event:

app.on('unknownCall', function(baseURI, method, callback, args...) {
// Your code goes here
});

iowamp NodeJS WAMP™ server - © 2012-2013 P. Mathis (dev@snapserv.net)

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