Example of logging into Github and getting user info using ReactiveCocoa and Octokit.

gistfile1.m

- (void)viewDidLoad {
    [super viewDidLoad];
    
    RAC(self.loginButton, enabled) = [RACSignal combineLatest:@[
                                      self.usernameTextField.rac_textSignal,
                                      self.passwordTextField.rac_textSignal]
                                                       reduce:^(NSString *username, NSString *password) {
                                                           return @([username length] > 0 && [password length] > 0);
                                                       }];
    
    [[self.loginButton rac_signalForControlEvents:UIControlEventTouchUpInside] subscribeNext:^(UIButton *sender) {
        [self.activity startAnimating];
        OCTUser *user = [OCTUser userWithLogin:self.usernameTextField.text server:OCTServer.dotComServer];
        OCTClient *client = [OCTClient authenticatedClientWithUser:user password:self.passwordTextField.text];
        [[client fetchUserInfo] subscribeNext:^(OCTUser *fetchedUser) {
            self.emailLabel.text = fetchedUser.email;
        } error:^(NSError *error) {
            NSLog(@"Fetching error: %@",error.localizedDescription);
        } completed:^{
            [self.activity stopAnimating];
        }];
    }];
}