sse-stream

Expose HTML5 Server Sent Events as an installable appliance on Node.JS http servers; connections are emitted as Writable streams.

``javascript

var http = require('http')
, fs = require('fs')
, through = require('through')
, sse = require('sse-stream')('/sse')
, serv

module.exports = serv = http.createServer(function(req, resp) {
resp.setHeader('content-type', 'text/html')
resp.end('')
})

sse.install(serv)

sse.on('connection', function(client) {
fs.createReadStream('/usr/share/dict/words')
.pipe(through(function(buf) { this.emit('data', buf.toString()) }))
.pipe(client)
})

// client-side code:
function js() {
var es = new EventSource('/sse')
, pre = document.createElement('pre')
, closed = false

document.body.appendChild(pre)

es.onmessage = function(ev) {
if(closed) return

pre.appendChild(document.createTextNode(ev.data))

window.scrollTo(0, pre.clientHeight)
}

es.addEventListener('end', function() {
es.close()
closed = true
}, true)

es.onerror = function(e) {
closed = true
}
}

`

API

$3

Create a SSE server that emits connection events on new, successful eventstream connections.

The argument may either be a string path to listen on (defaults to /sse/) or an object:

`javascript
{ path: '/listen/on/this/path'
, keepalive: 1000 }
`

keepalive determines the interval time in ms that keepalives will be sent to all connected clients.

$3

client` is a writable stream representing a client connection (request response pair).

Of note, all data sent through this connection will be stringified before sending due to
the event stream spec.

$3

Send a "retry" message that lets the client know how many MS to wait until retrying a connection that ended.

license

MIT