A Collection of code snippets for my reference for iOS project, (UPDATED on regular basis).

Extension.swift

//MARK: 01
extension UIView {
    // Using a function since `var image` might conflict with an existing variable
    // (like on `UIImageView`)
    func asImage() -> UIImage {
        if #available(iOS 10.0, *) {
            let renderer = UIGraphicsImageRenderer(bounds: bounds)
            return renderer.image { rendererContext in
                layer.render(in: rendererContext.cgContext)
            }
        } else {
            UIGraphicsBeginImageContext(self.frame.size)
            self.layer.render(in:UIGraphicsGetCurrentContext()!)
            let image = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
            return UIImage(cgImage: image!.cgImage!)
        }
    }
}
/*
//TODO: Usage
let myView = UIView()
let myImageFromMyView = graphImage.asImage()
*/

//MARK: 01
//TODO: Hide Keyboard when clicked around
extension UIViewController {
    func hideKeyboardWhenTappedAround() {
        let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(UIViewController.dismissKeyboard))
        view.addGestureRecognizer(tap)
    }
    
    func dismissKeyboard() {
        view.endEditing(true)
    }
}

//MARK: 03
//TODO: check if the app launched for the first time
extension UIApplication {
    class func isFirstLaunch() -> Bool {
        if !NSUserDefaults.standardUserDefaults().boolForKey("HasAtLeastLaunchedOnce") {
            NSUserDefaults.standardUserDefaults().setBool(true, forKey: "HasAtLeastLaunchedOnce")
            NSUserDefaults.standardUserDefaults().synchronize()
            return true
        }
        return false
    }
}

//TODO: Call it inside appDelegate > didFinishLaunchingWithOptions
if UIApplication.isFirstLaunch() {
    // do something on first launch
} else {
    // go ahead with regular launch
}

//MARK: 04 / Also check repo iOS App Security for obj-c complete implementation
//TODO: Add this inside launchScreenViewController.swift > viewDidLoad()
override func viewDidLoad() {
        super.viewDidLoad()
        
        if UIDevice.current.isJailBroken() {
            
            let jailbreakVC = JailBrokenViewController()
            self.navigationController?.present(jailbreakVC, animated: true, completion:nil)
            
        } else {
          //Continue to execute further
        }
}
      
//TODO: Add below as extension
extension UIDevice {
    func isJailBroken() -> Bool {
        var jailBroken = false
        let cydiaPath = "/Applications/Cydia.app"
        let aptPath = "/private/var/lib/apt/"
        if FileManager.default.fileExists(atPath: cydiaPath) {
            jailBroken = true
        }
        if FileManager.default.fileExists(atPath: aptPath) {
            jailBroken = true
        }
        return jailBroken
    }
}
//MARK: 05
//TODO: Add this outside / as a global method to be called
func performUIUpdatesOnMain(_ updates: @escaping () -> Void) {
    DispatchQueue.main.async {
        updates()
    }
}

//TODO: Use it anywhere you want to run things on main thread
performUIUpdatesOnMain {
  //MARK: for example, get use image recieved in data form
  //self.storyImage.image = UIImage(data: image)
}

//MARK: 06
//TODO: Resize Image
func resizeImage(image: UIImage, newWidth: CGFloat) -> UIImage {
        
        let scale = newWidth / image.size.width
        let newHeight = image.size.height * scale
        
        UIGraphicsBeginImageContext(CGSize(width: newWidth, height: newHeight))
        
        
        image.draw(in: CGRect(x: 0, y: 0,width: newWidth, height: newHeight))
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        
        return newImage!
 }
    
 func resizeToScreenSize(image: UIImage)->UIImage{
        
        let screenSize = self.view.bounds.size

        
        return resizeImage(image: image, newWidth: screenSize.width)
 }

//MARK: 07