foreachasync
v5.1.3
Published
A node- and browser-ready async (now with promises) counterpart of Array.prototype.forEach
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Readme
forEachAsync.js
| A Root project
Analogous to [].forEach
, but handles items asynchronously with a final callback passed to then
.
This is the most essential piece of the ArrayAsync
package.
For cases where you want to loop through batches of items at once (as opposed to strictly one-by-one as forEachAsync does), check out forAllAsync
and lateral
.
For cases where you want to loop through all items at once and we able to know when they're all done see join
v5.x
We jumped from 3.x to 5.x because I'm considering creating a backwards-and-forwards compatible 4.x that uses AngularJS-style function introspection to allow for having the next param. Straight up, that's probably a bad idea and waste of time so I hope I don't actually do it.
Screencast
Usage
// EXAMPLE ASYNC FUNCTION
function getPicsAsync(animal) {
var flickerApi = "http://api.flickr.com/services/feeds/photos_public.gne?tagmode=any&format=json&tags=" + animal;
return requestAsync({ url: flickerApi });
}
forEachAsync(['dogs', 'cats', 'octocats'], function (element) {
return getPicsAsync(element);
}).then(function () {
// then after all of the elements have been handled
// the final callback fires to let you know it's all done
console.log('All requests have finished');
});
Supplying your own Promises Implementation
If native ES6 promises are not available, then you should supply your own Promises/A+ implementation like so:
forEachAsync = forEachAsync.create(window.Promise || require('bluebird'));
Browser Installation
You can install from bower:
bower install --save [email protected]
Or download the raw file from https://git.coolaj86.com/coolaj86/foreachasync.js/raw/branch/master/foreachasync.js:
wget https://git.coolaj86.com/coolaj86/foreachasync.js/raw/branch/master/foreachasync.js
(function () {
'use strict';
var forEachAsync = window.forEachAsync;
// do stuff ...
}());
Note: If you need both 3.x/4.x and 5.x version of forEachAsync
in the browser... good luck with that...
Node Installation
npm install --save [email protected]
API
forEachAsync(array, callback[, thisArg])
Parameters
array
Array of elements to iterate overcallback
Function to execute for each element, takes 4 argumentselement
a single element of the aforementioned arrayindex
the index of the current elementarray
the same array mentioned above
thisArg
Object to use asthis
when executingcallback
forEachAsync#then(done)
Parameters
then
is in the return value offorEachAsync
and accepts a finaldone
callback.done
called afterforEachAsync
is complete, takes no arguments
Internal API
forEachAsync.__BREAK
This is used internally for the purposes of the ArrayAsync
library.
Please don't break
stuff; use ArrayAsync
.someAsync
or ArrayAsync
.everyAsync
instead.