Simple Server-Sent Events

A really simple library to work with Server-Sent Events in Node.js

> Mozilla Reference

Installation

You can use npm module, or just copy lib/index.js into your own package!

npm install --save simple-sse

Don't forget to require it ! var sse = require("simple-sse");

To work, this module requires a http server. You can use express.

Usage

This library is for a global use in your application (e.g. you don't have to call new instances). It's designed to work with rooms for several jobs in your application.

Here is the API :

####sse.add(req, res)

Register a client using it's own http req and res object. You can add this instruction in a classic route. For example :

app.get('/realtime', function(req, res) {
	sse.add(req, res);
});

Returns a SSE client.

####sse.setRetry(client, retry)

Send retry interval to a specified client. If the browser lose connection to the server, it will wait retry ms before reconnecting.

####sse.join(client, room)

When a client has to join a particular room. A client can join several rooms.

app.get('/room/:roomId', function(req, res) {
	var client = sse.add(req, res);
	sse.join(client, parseInt(req.params.roomId));
});

####sse.leave(client, room)

To leave a room.

####sse.in(client, room)

Returns true if the client is in the room. Room "*" will always return true.

####sse.send(client, [event], data)

Send an event to the client. Data can be multiline or an object, Simple-SSE will parse it correctly.

####sse.broadcast(room, [event], data)

Send an event to each client in "room" room. "room" parameter can be "*".

####sse.remove(client)

Remove a client for Simple-SSE store. It will not close the connection to the client. Used internally when a client closes the connection.

####sse.heartbeat

Heartbeat interval in ms. Default: 20000.

Client-side ?

Here is an example for a javascript client.

var source = new EventSource("/link");
source.addEventListener("eventName", function(e) {
    console.log(e.data);
});
source.onmessage = function(e) {
    //called when data is provided without event name
}
source.onopen = function(e) {
    //called when socket is listenning
}
source.onerror = function(e) {
    source.close();
}

Test

If you have cloned/forked this repository, you can test it with mocha. Just type npm test in simple-sse directory.

Changelog

v0.0.3

• Now works with node v0.12

v0.0.2

• Added retry(client, retry) function.
• Added heartbeat system to avoid connection loss if no data is passed. (not tested for now)

Enjoy !

This is a very simple library, but don't hesitate to fork and send pull requests :)