Anatoli-Petrosyants

extension UIViewController {
    func add(_ child: UIViewController) {
        addChildViewController(child)
        view.addSubview(child.view)
        child.didMove(toParentViewController: self)
    }

    func remove() {
        guard parent != nil else {
            return

Anatoli-Petrosyants

extension UIColor {
  
    convenience init(hex: Int, alpha: Double = 1.0) {
        let r = CGFloat((hex & 0xFF0000) >> 16) / 255.0
        let g = CGFloat((hex & 0x00FF00) >> 8) / 255.0
        let b = CGFloat(hex & 0x0000FF) / 255.0
        self.init(red: r, green: g, blue: b, alpha: CGFloat(alpha))
    }
}

Anatoli-Petrosyants

extension UIColor {
  
    convenience init(hex: Int, alpha: Double = 1.0) {
        let r = CGFloat((hex & 0xFF0000) >> 16) / 255.0
        let g = CGFloat((hex & 0x00FF00) >> 8) / 255.0
        let b = CGFloat(hex & 0x0000FF) / 255.0
        self.init(red: r, green: g, blue: b, alpha: CGFloat(alpha))
    }
}

Anatoli-Petrosyants

extension UIScreen {
    
    var screenwidth: CGFloat {
        return UIScreen.main.bounds.size.width
    }

    var screenHeight: CGFloat {
        return UIScreen.main.bounds.size.height
    }
}

Anatoli-Petrosyants

extension UIWebView {
   
    var userAgent: String {        
        get {
            return self.stringByEvaluatingJavaScript(from: "navigator.userAgent")!
        }
    }

Anatoli-Petrosyants

extension UITextView {
    
    public func clear() {
        text = ""
        attributedText = NSAttributedString(string: "")
    }
    
    public func scrollToBottom() {
        let range = NSMakeRange((text as NSString).length - 1, 1)
        scrollRangeToVisible(range)

Anatoli-Petrosyants

extension UIView {
    
    // In order to create computed properties for extensions, we need a key to
    // store and access the stored property
    fileprivate struct AssociatedObjectKeys {
        static var tapGestureRecognizer = "MediaViewerAssociatedObjectKey_mediaViewer"
    }
    
    fileprivate typealias Action = (() -> Void)?

Anatoli-Petrosyants

extension String {
    var html2AttributedString: NSAttributedString? {
        do {
            return try NSAttributedString(data: Data(utf8),
                                          options: [.documentType: NSAttributedString.DocumentType.html,
                                                    .characterEncoding: String.Encoding.utf8.rawValue],
                                          documentAttributes: nil)
        } catch {
            print("error: ", error)
            return nil

Anatoli-Petrosyants

extension UILayoutPriority {
    static func +(lhs: UILayoutPriority, rhs: Float) -> UILayoutPriority {
        let raw = lhs.rawValue + rhs
        return UILayoutPriority(rawValue:raw)
    }
}

Anatoli-Petrosyants

extension UITextField {
    
    public var isEmpty: Bool {
        if let text = self.text {
            return text.isEmpty
        }
        return true
    }
    
    public var trimmedText: String? {