Sample for using Fabric in RubyMotion

login_controller.rb

class LoginController < UIViewController
  def viewDidLoad
    super

    @button = TWTRLogInButton.buttonWithLogInCompletion Proc.new {|session, error|
      if error 
        NSLog("Error : #{error}")
      else 
        NSLog("UserName : #{session.userName}")

        App.window.rootViewController = TimelineController.alloc.initWithNibName(nil, bundle: nil)
      end
    }

    @button.center = self.view.center
    self.view.addSubview @button
  end
end