1 | #through
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2 |
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3 | [![build status](https://secure.travis-ci.org/dominictarr/through.png)](http://travis-ci.org/dominictarr/through)
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4 | [![testling badge](https://ci.testling.com/dominictarr/through.png)](https://ci.testling.com/dominictarr/through)
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5 |
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6 | Easy way to create a `Stream` that is both `readable` and `writable`.
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7 |
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8 | * Pass in optional `write` and `end` methods.
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9 | * `through` takes care of pause/resume logic if you use `this.queue(data)` instead of `this.emit('data', data)`.
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10 | * Use `this.pause()` and `this.resume()` to manage flow.
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11 | * Check `this.paused` to see current flow state. (`write` always returns `!this.paused`).
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12 |
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13 | This function is the basis for most of the synchronous streams in
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14 | [event-stream](http://github.com/dominictarr/event-stream).
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15 |
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16 | ``` js
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17 | var through = require('through')
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18 |
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19 | through(function write(data) {
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20 | this.queue(data) //data *must* not be null
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21 | },
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22 | function end () { //optional
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23 | this.queue(null)
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24 | })
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25 | ```
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26 |
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27 | Or, can also be used _without_ buffering on pause, use `this.emit('data', data)`,
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28 | and this.emit('end')
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29 |
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30 | ``` js
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31 | var through = require('through')
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32 |
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33 | through(function write(data) {
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34 | this.emit('data', data)
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35 | //this.pause()
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36 | },
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37 | function end () { //optional
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38 | this.emit('end')
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39 | })
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40 | ```
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41 |
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42 | ## Extended Options
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43 |
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44 | You will probably not need these 99% of the time.
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45 |
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46 | ### autoDestroy=false
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47 |
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48 | By default, `through` emits close when the writable
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49 | and readable side of the stream has ended.
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50 | If that is not desired, set `autoDestroy=false`.
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51 |
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52 | ``` js
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53 | var through = require('through')
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54 |
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55 | //like this
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56 | var ts = through(write, end, {autoDestroy: false})
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57 | //or like this
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58 | var ts = through(write, end)
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59 | ts.autoDestroy = false
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60 | ```
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61 |
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62 | ## License
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63 |
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64 | MIT / Apache2
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