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author | Florian Dold <florian.dold@gmail.com> | 2016-10-10 03:43:44 +0200 |
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committer | Florian Dold <florian.dold@gmail.com> | 2016-10-10 03:43:44 +0200 |
commit | abd94a7f5a50f43c797a11b53549ae48fff667c3 (patch) | |
tree | ab8ed457f65cdd72e13e0571d2975729428f1551 /node_modules/map-stream/readme.markdown | |
parent | a0247c6a3fd6a09a41a7e35a3441324c4dcb58be (diff) |
add node_modules to address #4364
Diffstat (limited to 'node_modules/map-stream/readme.markdown')
-rw-r--r-- | node_modules/map-stream/readme.markdown | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/node_modules/map-stream/readme.markdown b/node_modules/map-stream/readme.markdown new file mode 100644 index 000000000..18971588d --- /dev/null +++ b/node_modules/map-stream/readme.markdown @@ -0,0 +1,37 @@ +# MapStream + +Refactored out of [event-stream](https://github.com/dominictarr/event-stream) + +##map (asyncFunction[, options]) + +Create a through stream from an asyncronous function. + +``` js +var map = require('map-stream') + +map(function (data, callback) { + //transform data + // ... + callback(null, data) +}) + +``` + +Each map MUST call the callback. It may callback with data, with an error or with no arguments, + + * `callback()` drop this data. + this makes the map work like `filter`, + note:`callback(null,null)` is not the same, and will emit `null` + + * `callback(null, newData)` turn data into newData + + * `callback(error)` emit an error for this item. + +>Note: if a callback is not called, `map` will think that it is still being processed, +>every call must be answered or the stream will not know when to end. +> +>Also, if the callback is called more than once, every call but the first will be ignored. + +##Options + + * `failures` - `boolean` continue mapping even if error occured. On error `map-stream` will emit `failure` event. (default: `false`) |