swift-calendar-view-controller.swift

override func viewDidLoad() {
	super.viewDidLoad()

	contentView.addSubview(collectionView)
	collectionView.topAnchor.constraint(equalTo: self.contentView.topAnchor, constant: 0).isActive = true
	collectionView.bottomAnchor.constraint(equalTo: self.contentView.bottomAnchor, constant: 0).isActive = true
	collectionView.leadingAnchor.constraint(equalTo: self.contentView.leadingAnchor, constant: 0).isActive = true
	collectionView.trailingAnchor.constraint(equalTo: self.contentView.trailingAnchor, constant: 0).isActive = true
}

lazy var collectionView: UICollectionView = {
  let layout = collectionViewFlowLayout
  let collectionView = UICollectionView(frame: self.contentView.frame, collectionViewLayout: layout)

  collectionView.backgroundColor = UIColor.white
  collectionView.translatesAutoresizingMaskIntoConstraints = false

  return collectionView
}()