I really like the EventEmitter paradigm, and I'd like to use it to communicate between two programs across a network.
I came up with my own SockEmitter, but I want to know: am I "doing it wrong(tm)"? Is there some package that will already do this? Is there a different paradigm that works better for communicating across a network?
Here's what I have:
var JsonSocket = require('json-socket')
// An event emitter that uses a JsonSocket.
// emit passes things over the wire, and data received
// over the wire calls the listeners.
//
// As a result, se.on('foo', console.log); se.emit('foo', 5)
// won't do what you might normally expect from an emitter.
function SockEmitter(socket) {
this._listeners = {}
this.sock = new JsonSocket(socket)
this.sock.on('message', this._message.bind(this))
}
SockEmitter.prototype = {
on: function (type, handler) {
if (!this._listeners[type]) {
this._listeners[type] = [];
}
this._listeners[type].push(handler)
},
off: function (type, handler) {
if (!this._listeners[type]) {
return false
}
var idx = this._listeners[type].indexOf(handler)
if (idx === -1) return false
this._listeners[type].splice(idx, 1)
},
emit: function (type) {
var args = [].slice.call(arguments, 1)
this.sock.sendMessage({type: type, args: args})
},
_message: function (message) {
if (!message || !message.type || !Array.isArray(message.args)) {
return console.error('Invalid message received: %s', message)
}
if (!this._listeners[message.type]) return
this._listeners[message.type].forEach(function (handler) {
handler.apply(null, message.args)
})
}
}
