gistfile1.js

.factory("injectCSS", ['$q', '$http', 'MeasurementsService', function($q, $http, MeasurementsService){
  var injectCSS = {};
  
  var createLink = function(id, url) {
    var link = document.createElement('link');
    link.id = id;
    link.rel = "stylesheet";
    link.type = "text/css";
    link.href = url;
    return link;
  }
  
  var checkLoaded = function (url, deferred, tries) {
    for (var i in document.styleSheets) {
      var href = document.styleSheets[i].href || "";
      if (href.split("/").slice(-1).join() === url) {
        deferred.resolve();
        return;
      }
    }
    tries++;
    setTimeout(function(){checkLoaded(url, deferred, tries);}, 50); 
  };
    
  injectCSS.set = function(id, url){
    var tries = 0,
      deferred = $q.defer(),
      link;
    
    if(!angular.element('link#' + id).length) {
      link = createLink(id, url);
      link.onload = deferred.resolve;
      angular.element('head').append(link);
    }
    checkLoaded(url, deferred, tries);
    
    return deferred.promise;
  };
  
  return injectCSS;
}])