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64 lines
1.5 KiB
64 lines
1.5 KiB
2 years ago
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# stream-events
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> Get an event when you're being sent data or asked for it.
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## About
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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.
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This works well with [duplexify](https://github.com/mafintosh/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.
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## Use
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```sh
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$ npm install --save stream-events
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```
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```js
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var stream = require('stream')
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var streamEvents = require('stream-events')
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var util = require('util')
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function MyStream() {
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stream.Duplex.call(this)
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streamEvents.call(this)
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}
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util.inherits(MyStream, stream.Duplex)
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MyStream.prototype._read = function(chunk) {
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console.log('_read called as usual')
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this.push(new Buffer(chunk))
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this.push(null)
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}
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MyStream.prototype._write = function() {
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console.log('_write called as usual')
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}
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var stream = new MyStream
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stream.on('reading', function() {
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console.log('stream is being asked for data')
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})
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stream.on('writing', function() {
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console.log('stream is being sent data')
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})
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stream.pipe(stream)
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```
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### Using with Duplexify
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```js
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var duplexify = require('duplexify')
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var streamEvents = require('stream-events')
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var fs = require('fs')
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var dup = streamEvents(duplexify())
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dup.on('writing', function() {
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// do something async
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dup.setWritable(/*writable stream*/)
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})
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fs.createReadStream('file').pipe(dup)
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```
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