JarCastingstream-events
Get an event when you're being sent data or asked for it.
About
This is just a simple thing that tells you when _read and _write have been called, saving you the trouble of writing this yourself. You receive two events reading and writing-- no magic is performed.
This works well with duplexify or lazy streams, so you can wait until you know you're being used as a stream to do something asynchronous, such as fetching an API token.
Use
$ npm install --save stream-events
var stream = require('stream')
var streamEvents = require('stream-events')
var util = require('util')
function MyStream() {
stream.Duplex.call(this)
streamEvents.call(this)
}
util.inherits(MyStream, stream.Duplex)
MyStream.prototype._read = function(chunk) {
console.log('_read called as usual')
this.push(new Buffer(chunk))
this.push(null)
}
MyStream.prototype._write = function() {
console.log('_write called as usual')
}
var stream = new MyStream
stream.on('reading', function() {
console.log('stream is being asked for data')
})
stream.on('writing', function() {
console.log('stream is being sent data')
})
stream.pipe(stream)
Using with Duplexify
var duplexify = require('duplexify')
var streamEvents = require('stream-events')
var fs = require('fs')
var dup = streamEvents(duplexify())
dup.on('writing', function() {
// do something async
dup.setWritable(/*writable stream*/)
})
fs.createReadStream('file').pipe(dup)