10-11-2014-4.swift

class MessageControl: UIView {

    @IBOutlet weak var textField: UITextField!
    @IBOutlet weak var actionButton: UIButton!
    
    override func awakeFromNib() {
        super.awakeFromNib()
        self.actionButton.enabled = false
    }
    
    override func awakeAfterUsingCoder(aDecoder: NSCoder) -> AnyObject? {
        if self.subviews.count == 0 {
            let nib = UINib(nibName: "MessageControl", bundle: nil)
            let view = nib.instantiateWithOwner(nil, options: nil).first! as MessageControl
            view.setTranslatesAutoresizingMaskIntoConstraints(false)
            return view
        }
        
        return self
    }
    
    @IBAction func onActionPressed(sender: AnyObject) {
        let success = self.sendMessage(self.textField.text)
        let message = success ? "Message sent" : "Message not send"
        UIAlertView(title: nil, message: message, delegate: nil, cancelButtonTitle: "Ok").show()
        
        if (success) {
            self.textField.text = ""
            self.validateActionButton()
        }
    }
    
    private func validateActionButton() {
        self.actionButton.enabled = countElements(self.textField.text) > 0
    }
    
    private func sendMessage(message: String) -> Bool {
        /// some logic here ...
        
        return true
    }
    
    @IBAction func textFieldDidChange(sender: AnyObject) {
        self.validateActionButton()
    }
    
}