Runs a list of async tasks, passing the results of each into the next one
Runs an array of functions in series, each passing their results to the next in the array. However, if any of the functions pass an error to the callback, the next function is not executed and the main callback is immediately called with the error.
For browsers and node.js.
- Just include async-waterfall before your scripts.
npm install async-waterfallif you’re using node.js.
component install es128/async-waterfallif you’re using component(1).
bower install async-waterfallif you’re using Twitter Bower.
- tasks - An array of functions to run, each function is passed a
callback(err, result1, result2, ...)it must call on completion. The first argument is an error (which can be null) and any further arguments will be passed as arguments in order to the next task.
- optionalCallback - An optional callback to run once all the functions have completed. This will be passed the results of the last task's callback.
var waterfall = require'async-waterfall';waterfalltasks callback;
// component(1)var waterfall = require'async-waterfall';waterfalltasks callback;// Default:windowasyncWaterfalltasks callback;
waterfallcallbacknull 'one' 'two';callbacknull 'three';// arg1 now equals 'three'callbacknull 'done';// result now equals 'done';
waterfallmyArraymapreturn// same execution for each item in the arrayvar itemResult = doThingsWitharrayItem lastItemResult;// results carried along from each to the nextnextCallbacknull itemResult;// final callback;
The MIT License (MIT)
Copyright (c) 2013 Elan Shanker
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.