mirror of https://github.com/thangisme/notes.git
75 lines
2.6 KiB
Markdown
75 lines
2.6 KiB
Markdown
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# Split2(matcher, mapper, options)
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[](http://travis-ci.org/mcollina/split2)
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Break up a stream and reassemble it so that each line is a chunk.
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`split2` is inspired by [@dominictarr](https://github.com/dominictarr) [`split`](https://github.com/dominictarr) module,
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and it is totally API compatible with it.
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However, it is based on [`through2`](https://github.com/rvagg/through2) by [@rvagg](https://github.com/rvagg) and it is fully based on Stream2.
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`matcher` may be a `String`, or a `RegExp`. Example, read every line in a file ...
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``` js
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fs.createReadStream(file)
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.pipe(split2())
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.on('data', function (line) {
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//each chunk now is a seperate line!
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})
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```
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`split` takes the same arguments as `string.split` except it defaults to '/\r?\n/' instead of ',', and the optional `limit` paremeter is ignored.
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[String#split](https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/split)
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`split` takes an optional options object on it's third argument, which
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is directly passed as a
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[Transform](http://nodejs.org/api/stream.html#stream_class_stream_transform_1)
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option.
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Calling `.destroy` will make the stream emit `close`. Use this to perform cleanup logic
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``` js
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var splitFile = function(filename) {
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var file = fs.createReadStream(filename)
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return file
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.pipe(split2())
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.on('close', function() {
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// destroy the file stream in case the split stream was destroyed
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file.destroy()
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})
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}
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var stream = splitFile('my-file.txt')
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stream.destroy() // will destroy the input file stream
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```
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# NDJ - Newline Delimited Json
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`split2` accepts a function which transforms each line.
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``` js
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fs.createReadStream(file)
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.pipe(split2(JSON.parse))
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.on('data', function (obj) {
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//each chunk now is a a js object
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})
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```
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# License
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Copyright (c) 2014, Matteo Collina <hello@matteocollina.com>
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Permission to use, copy, modify, and/or distribute this software for any
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purpose with or without fee is hereby granted, provided that the above
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copyright notice and this permission notice appear in all copies.
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THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
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IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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