let urlText = "http://www.apple.com"
let url = NSURL(string: urlText)!
let safariViewController = SFSafariViewController(URL: url)
self.navigationController?.pushViewController(safariViewController, animated: true)

let sfController = SFSafariViewController(URL: NSURL(string:"url")!)
sfController.modalPresentationStyle = .FormSheet
sfController.modalTransitionStyle = .CrossDissolve
presentViewController(sfController, animated: false, completion: nil)