Auth promises and callbacks

[kingcody]

Looking over client/components/auth/auth.service it seems that it would be beneficial for us to use a signature for the methods that would allow for synchronous and async callback/promises.

I would propose:

function(callback, safe) {
  if (arguments.length === 0) {
    return synchronous.result;
  } else {
    var deferred = $q.defer();
    async.then(function(data) {
      deferred.resolve(data);
      callback(data);
    }, function() {
      (safe) ? deferred.resolve(null) : deferred.reject();
      callback(null);
    });
    return deferred.promise;
  }
}

Its not terribly complicated and I feel provides maximum usability. Such as, all current calls to the auth methods would be maintained sync, we could remove methods such as isLoggedInAsync, and also we could use the promises they return in resolves for routes which could seriously improve the routing authentication.

I'd also like to point out the use of the 2nd argument safe, I've used it to allow us to receive promises that only resolve and not reject. This could be useful in a route resolve as well, being that if a promise is rejected then $routeChangeError or $stateChangeError is fired and we may not always want that.

Another advantage would be that you could chain the promises with finer grained control, dictating whether or not a promise resolves into another (even on error) or is rejected and the chain canceled.

[kingcody]

With the release of angular 1.3.0 (still beta atm), $q receives some notable upgrades that would allow us to simplify the process even more.

[kingcody]

After more investigation, I think that resolves wouldn't (at this time) be suited for authentication in routes. However is still feel that returning promises from the Auth methods would still be beneficial.

Examples:

_Auth.getCurrentUser_

getCurrentUser: function(cb) {
  if (arguments.length === 0) {
    return currentUser;
  } else {
    var value = (currentUser.hasOwnProperty('$promise')) ? currentUser.$promise : currentUser;
    cb = safeCb(cb);
    return $q.when(value)
      .then(function(user) {
        cb(user);
        return user;
      })
      .catch(function() {
        cb({});
        return {};
      });
  }
}

_Auth.isLoggedIn_

isLoggedIn: function(cb) {
  if (arguments.length === 0) {
    return currentUser.hasOwnProperty('role');
  } else {
    cb = safeCb(cb);
    return this.getCurrentUser(null)
      .then(function(user) {
        var is = user.hasOwnProperty('role');
        cb(is);
        return is;
      });
  }
}

_Auth.isAdmin_

isAdmin: function(cb) {
  if (arguments.length === 0) {
    return currentUser.role === 'admin';
  } else {
    cb = safeCb(cb);
    return this.getCurrentUser(null)
      .then(function(user) {
        var is = user.role === 'admin';
        cb(is);
        return is;
      });
  }
}

Still allows for use as route resolves, and synchronous code by not passing any arguments.

Just some 'opinions'...

[DaftMonk]

That looks good. Much cleaner.

[kingcody]

@DaftMonk you can checkout this branch if you'd like to see my changes.

[sparqueur]

Hi,
Just a little question about the way access the currentUser in a controler safely.
I currently load it in my controler this way :

alert ( Auth.getCurrentUser().name );

Unfortunatly sometimes retrieving the user (when refreshing page) takes too much time --> undefined

Workaround for me :

User.get().$promise.then( function(user) {
    alert ( user.name );
}

I would prefer accessing currentUser through Auth service (but perhaps I'm just wrong).

Note : I am just trying to enhance my user "settings" page

Thanks in advance

[kingcody]

@sparqueur check out #465. In auth.service.js the method getCurrentUser is written to be synchronous/asynchronous. When used asynchronously it should provide you with the user object after its resolved.

[sparqueur]

Ho, sorry. Think I was a little tired...
Thanks for this cool generator which made me win a lot of time.

[kingcody]

@sparqueur no problem. Hope that helps you out 😄

[kingcody]

Closed by #465