Promises-based AJAX transactions

promise.js

var endpoints = ['/data/step1', '/data/step2', '/data/step3'];
// this will hold our promises
var promises  = [];

$.each(endpoints, function(index, url){
  // push the returned promise from $.get to our array
  promises.push($.get(url));
})

// $.when takes a list of promises, we will use apply to pass an arbitrary number of arguments
$.when.apply($, promises).done(function(){
  console.log('Promise is complete')
}).fail(function(jqXHR, textStatus, errorThrown){
  console.log('Not all conditions were met');
  console.log("Error: %s (%s)", textStatus, errorThrown);
});