Writing a login view for a mobile app is typically a lot of work. The complexity originates partially from the the multitude of login options your mobile app may support; username/password, Facebook, Twitter are among the popular choices. In addition, the login controller needs to handle the cases when the device is offline, when the user forgets his username/password, or when the server is down. Worst of all, just before you think you are done, you need to write a similar controller for sign up.

The above considerations make writing a login screen a daunting task.
Today, we are going to change that with the release of a drop-in view controller which handles all these edge cases for you.

Welcome to PFLogInViewController in the Parse framework. With this class, creating a functional login view controller literally takes a minute. All you need to do is to create it and present it modally:

PFLogInViewController *logInController = [[PFLogInViewController alloc] init];
logInController.delegate = self;
[self presentModalViewController:logInController animated:YES];

With these few lines of code, you will get a beautiful login screen, which is shown below. By default, it comes with login functionalities that include username/password field, a password forgotten button, and a sign up button.

Default PFLogInViewController

PFLogInViewController with all elements

Reskinned PFLogInViewController

What if you also want to support Facebook and Twitter? The PFLogInViewController class is configurable, which means you can turn any feature on and off:

PFLogInViewController *logInController = [[PFLogInViewController alloc] init];
logInController.delegate = self;
logInController.fields = PFLogInFieldsDefault 
                | PFLogInFieldsFacebookButton | PFLogInFieldsTwitterButton;
[self presentModalViewController:logInController animated:YES];

Now you are getting a login view controller that works with Facebook and Twitter. It looks great, and it works on the iPhone, iPad, portrait and landscape.

The following tutorial takes a more in-depth look at the new class:

Read more in our iOS guide. As always, any feedback is welcome.