80 lines
2.1 KiB
Markdown
80 lines
2.1 KiB
Markdown
Run Async
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=========
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[](http://badge.fury.io/js/run-async) [](http://travis-ci.org/SBoudrias/run-async) [](https://david-dm.org/SBoudrias/run-async)
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Utility method to run a function either synchronously or asynchronously using a series of common patterns. This is useful for library author accepting sync or async functions as parameter. `runAsync` will always run them as an async method, and normalize the multiple signature.
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Installation
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=========
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```bash
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npm install --save run-async
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```
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Usage
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=========
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Here's a simple example print the function results and three options a user can provide a function.
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```js
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var runAsync = require('run-async');
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var printAfter = function (func) {
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var cb = function (err, returnValue) {
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console.log(returnValue);
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};
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runAsync(func, cb)(/* arguments for func */);
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};
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```
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#### Using `this.async`
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```js
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printAfter(function () {
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var done = this.async();
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setTimeout(function () {
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done(null, 'done running with callback');
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}, 10);
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});
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```
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#### Returning a promise
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```js
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printAfter(function () {
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return new Promise(function (resolve, reject) {
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resolve('done running with promises');
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});
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});
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```
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#### Synchronous function
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```js
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printAfter(function () {
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return 'done running sync function';
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});
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```
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### runAsync.cb
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`runAsync.cb` supports all the function types that `runAsync` does and additionally a traditional **callback as the last argument** signature:
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```js
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var runAsync = require('run-async');
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// IMPORTANT: The wrapped function must have a fixed number of parameters.
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runAsync.cb(function(a, b, cb) {
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cb(null, a + b);
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}, function(err, result) {
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console.log(result)
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})(1, 2)
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```
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If your version of node support Promises natively (node >= 0.12), `runAsync` will return a promise. Example: `runAsync(func)(arg1, arg2).then(cb)`
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Licence
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========
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Copyright (c) 2014 Simon Boudrias (twitter: @vaxilart)
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Licensed under the MIT license.
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