gistfile1.swift

import UIKit

class AuthenticationViewController: UIViewController {
    
    // MARK: - Properties
    var welcomeLabel: UILabel = {
        let label = UILabel()
        label.text = "Welcome to Paparazzi"
        label.setTranslatesAutoresizingMaskIntoConstraints(false)
        label.font = UIFont(name: "HelveticaNeue-Thin", size: 30)
        label.textAlignment = .Center
        return label
    }()
    
    var descriptionLabel: UILabel {
        let label = UILabel()
        label.text = "We'll text your phone number a confirmation code to get going."
        label.setTranslatesAutoresizingMaskIntoConstraints(false)
        label.font = UIFont(name: "HelveticaNeue-Thin", size: 14)
        label.textColor = UIColor(red: 0.400, green: 0.400, blue: 0.400, alpha: 1)
        label.numberOfLines = 0
        label.textAlignment = .Center
        return label
    }
    
    override func prefersStatusBarHidden() -> Bool {
        return true
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        navigationController.setNavigationBarHidden(true, animated: false)
        view.backgroundColor = UIColor.whiteColor()
        
        view.addSubview(welcomeLabel)
        view.addSubview(descriptionLabel)
        
        setupConstraints()
    }
        
    func setupConstraints() {
        let views = [
            "welcomeLabel": welcomeLabel,
            "descriptionLabel": descriptionLabel
        ]
        
        let metrics = [
            "topPadding": 30,
            "margin": 12
        ]
        
        view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("|-(margin)-[welcomeLabel]-(margin)-|", options: nil, metrics: metrics, views: views))
        view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|-(topPadding)-[welcomeLabel]", options: nil, metrics: metrics, views: views))
        view.addConstraint(NSLayoutConstraint(item: descriptionLabel, attribute: .CenterY, relatedBy: .Equal, toItem: welcomeLabel, attribute: .CenterY, multiplier: 1, constant: 0))
    }
    
}

2014-08-10 12:19:35.774 TestApp[2657:60b] *** -[UILabel superview]: message sent to deallocated instance 0x135d14820