#through [](http://travis-ci.org/dominictarr/through) [](https://ci.testling.com/dominictarr/through) Easy way to create a `Stream` that is both `readable` and `writable`. * Pass in optional `write` and `end` methods. * `through` takes care of pause/resume logic if you use `this.queue(data)` instead of `this.emit('data', data)`. * Use `this.pause()` and `this.resume()` to manage flow. * Check `this.paused` to see current flow state. (`write` always returns `!this.paused`). This function is the basis for most of the synchronous streams in [event-stream](http://github.com/dominictarr/event-stream). ``` js var through = require('through') through(function write(data) { this.queue(data) //data *must* not be null }, function end () { //optional this.queue(null) }) ``` Or, can also be used _without_ buffering on pause, use `this.emit('data', data)`, and this.emit('end') ``` js var through = require('through') through(function write(data) { this.emit('data', data) //this.pause() }, function end () { //optional this.emit('end') }) ``` ## Extended Options You will probably not need these 99% of the time. ### autoDestroy=false By default, `through` emits close when the writable and readable side of the stream has ended. If that is not desired, set `autoDestroy=false`. ``` js var through = require('through') //like this var ts = through(write, end, {autoDestroy: false}) //or like this var ts = through(write, end) ts.autoDestroy = false ``` ## License MIT / Apache2