Turn event emitters into streams and streams into event emitters. Streams3 version of emit-stream.
npm install emit-stream3Turn event emitters into streams and streams into event emitters. Streams3
version of emit-stream.
Borrowing from the original README, let's write a server that streams
an event emitter's _events_ to clients:
``js
const emitStream = require('emit-stream3')
const JSONStream = require('JSONStream')
const net = require('net')
const EventEmitter = require('events').EventEmitter
const server = (function () {
const ev = createEmitter()
return net.createServer(stream =>
emitStream(ev)
.pipe(JSONStream.stringify())
.pipe(stream)
)
})()
server.listen(5555)
function createEmitter () {
const ev = new EventEmitter
setInterval(() => ev.emit('ping', Date.now()), 2000)
let x = 0
setInterval(() => ev.emit('x', x ++), 500)
return ev
}
`
Then re-constitute the event emitters on the client:
` js
const emitStream = require('emit-stream3')
const net = require('net')
const stream = net.connect(5555).pipe(JSONStream.parse([true]))
const ev = emitStream(stream)
ev.on('ping', t => console.log('# ping: ' + t))
ev.on('x', x => console.log('x = ' + x))
`
Outputting:
` `
$ node example/emit.js
x = 0
x = 1
x = 2
x = 3 ping: 1346116850523
x = 4
x = 5
^C
` js`
const emitStream = require('emit-stream3')
If x is a stream, returns an event emitter from emit.toStream(x). emit.fromStream(x)
Otherwise, it returns a stream from .
Return a stream from the EventEmitter emitter.
The 'data' emitted by this stream will be an array. Serialization is
up to you. I recommend JSONStream
for most purposes.
Return an EventEmitter from stream.
The 'data' written to this stream should be an array, like
JSONStream creates.
With npm do:
`
npm install emit-stream3