82 lines
2.7 KiB
Markdown
82 lines
2.7 KiB
Markdown
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# @ljharb/through <sup>[![Version Badge][npm-version-svg]][package-url]</sup>
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*Note*: This package is a fork of https://npmjs.com/through, and builds off of it.
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[![github actions][actions-image]][actions-url]
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[![coverage][codecov-image]][codecov-url]
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[![License][license-image]][license-url]
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[![Downloads][downloads-image]][downloads-url]
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[![npm badge][npm-badge-png]][package-url]
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Easy way to create a `Stream` that is both `readable` and `writable`.
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* Pass in optional `write` and `end` methods.
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* `through` takes care of pause/resume logic if you use `this.queue(data)` instead of `this.emit('data', data)`.
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* Use `this.pause()` and `this.resume()` to manage flow.
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* Check `this.paused` to see current flow state. (`write` always returns `!this.paused`).
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This function is the basis for most of the synchronous streams in [event-stream](http://github.com/dominictarr/event-stream).
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``` js
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var through = require('@ljharb/through')
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through(function write(data) {
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this.queue(data) //data *must* not be null
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},
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function end () { //optional
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this.queue(null)
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})
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```
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Or, can also be used _without_ buffering on pause, use `this.emit('data', data)`,
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and this.emit('end')
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``` js
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var through = require('@ljharb/through')
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through(function write(data) {
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this.emit('data', data)
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//this.pause()
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},
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function end () { //optional
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this.emit('end')
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})
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```
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## Extended Options
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You will probably not need these 99% of the time.
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### autoDestroy=false
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By default, `through` emits close when the writable
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and readable side of the stream has ended.
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If that is not desired, set `autoDestroy=false`.
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``` js
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var through = require('@ljharb/through')
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//like this
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var ts = through(write, end, {autoDestroy: false})
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//or like this
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var ts = through(write, end)
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ts.autoDestroy = false
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```
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[package-url]: https://npmjs.org/package/@ljharb/through
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[npm-version-svg]: https://versionbadg.es/ljharb/through.svg
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[deps-svg]: https://david-dm.org/ljharb/through.svg
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[deps-url]: https://david-dm.org/ljharb/through
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[dev-deps-svg]: https://david-dm.org/ljharb/through/dev-status.svg
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[dev-deps-url]: https://david-dm.org/ljharb/through#info=devDependencies
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[npm-badge-png]: https://nodei.co/npm/@ljharb/through.png?downloads=true&stars=true
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[license-image]: https://img.shields.io/npm/l/@ljharb/through.svg
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[license-url]: LICENSE
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[downloads-image]: https://img.shields.io/npm/dm/@ljharb/through.svg
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[downloads-url]: https://npm-stat.com/charts.html?package=@ljharb/through
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[codecov-image]: https://codecov.io/gh/ljharb/through/branch/main/graphs/badge.svg
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[codecov-url]: https://app.codecov.io/gh/ljharb/through/
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[actions-image]: https://img.shields.io/endpoint?url=https://github-actions-badge-u3jn4tfpocch.runkit.sh/ljharb/through
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[actions-url]: https://github.com/ljharb/through/actions
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