Mastering JavaScript Promises

Concurrency in Angular.js

We all want to achieve maximum output at a single slot of time by asking multiple services to invoke and get results from them. Angular.js provides this functionality via its $q.all service; you can invoke many services at a time and if you want to join all/any of them, you just need then() to get them together in the sequence you want.

Let's get the payload of the array first:

[ 
  { url: 'myUr1.html' },
  { url: 'myUr2.html' },
  { url: 'myUr3.html' }
]

And now this array will be used by the following code:

service('asyncService', function($http, $q) { return { getDataFrmUrls: function(urls) { var deferred = $q.defer(); var collectCalls = []; angular.forEach(urls, function(url) { collectCalls.push($http.get(url.url)); }); $q.all(collectCalls) ...