Authenticate a user with angularfire, save to firebase, and make available to controllers with promise

app.js

/*

This file is a brief example of how to use angularfire to authenticate a user, save that user's public profile to firebase, then 
ensure that both the authenticated and public user are available in your controllers. 

The route configuration uses angular-ui-router:  https://github.com/angular-ui/ui-router

*/


//***********in services.js ****************

angular.module('myapp.services', [])

//simpleLogin service for angularfire, as described in angularfire docs  
//https://www.firebase.com/docs/web/libraries/angular/api.html#angularfire-firebasesimplelogin
.factory("simpleLogin", ["$firebaseSimpleLogin", "$firebase", function($firebaseSimpleLogin, $firebase){
  var ref = new Firebase("your_url_here");
  var authProvider = $firebaseSimpleLogin(ref);
  return authProvider;
}])

.factory("userPromise", ["simpleLogin", "$firebase", "$q", function(simpleLogin, $firebase, $q) {
  //function returnPromise will generate a promise that will get the authenticated user, make a profile if it doesn't exist,
  //and then return both objects on resolution. 
  var returnPromise = function(){
    var user, publicUser;  
    var deferred = $q.defer();
    
    //this function will take a user object and check for existing profile "publicUser" and create it if not
    var getPublicUser = function(auth_user){
      var ref = new Firebase("your_firebase_url");
      var remoteUser = $firebase(ref.child('users').child(auth_user.uid)).$asObject();
      remoteUser.$loaded().then(function(){
        if (remoteUser.profile){
          deferred.notify('Existing public profile');
          publicUser = remoteUser;
          deferred.resolve({user: user, publicUser: publicUser});
        } else {
          deferred.notify('New user - initializing profile');
          remoteUser.displayName = auth_user.displayName;
          remoteUser.provider = auth_user.provider;
          remoteUser.provider_id = auth_user.id;
          remoteUser.provider_username = auth_user.username;
          remoteUser.profile_img_url = auth_user.thirdPartyUserData.profile_image_url;
          remoteUser.profile = {};
          remoteUser.$save(function(){console.log('successfully saved')});  //save to firebase
          publicUser = remoteUser;
          deferred.resolve({user: user, publicUser: publicUser});
        } 
      });
    }
    
    //get the authenticated user
    simpleLogin.$getCurrentUser().then(function(userData){
      if(userData){
        deferred.notify('User ' + userData.id + " successfully logged in through simpleLogin");
        user = userData;
        //if authenticated, get the public object
        getPublicUser(userData);
      } else {
        deferred.reject('Not authenticated')
      }
    });
    
    //return promise
    return deferred.promise;
  }
  //return function to generate the promise. We return a function instead of
  //the promise directly so they can regenerate the promise if they fail authentication.
  return {getPromise: returnPromise};
  
}]);

//************************* in app.js ***************************
//Example of how to use angular-ui-routes to ensure user is logged in
// & that the promise is resolved before your controllers are initialized

angular.module('myapp', ['myapp.services', 'myapp.controllers', 'firebase'])

.config(function($stateProvider, $urlRouterProvider) {
  
  $stateProvider.state('example', {
    url: "/example",
    templateUrl: "templates/example.html",
    resolve: {
      "currentUser": 
          ["userPromise", "$state", function(userPromise, $state) {
            return userPromise.getPromise().then(function(success){
              return success;
            }, function(reason){
              console.log("userPromise Failed: " + reason);
              $state.transitionTo('login');
            }, function(notification){
              console.log("notification: " + notification);
             });  
          }]
    }
  });
}

//************************* in controllers.js ***************************
//you can inject currentUser and immediately retrieve the objects 
//as the promise will be resolved before ExampleCtrl is initialized

angular.module('myapp.controllers', [])

.controller('ExampleCtrl', ["$scope", "currentUser", function($scope, currentUser) {
  $scope.user = currentUser.user //returns the authenticated user object
  $scope.profile = currentUser.publicUser; //returns the public user object we created earlier
}