Swift Dynamic UITableView Header View

gistfile1.swift

override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
    super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
    self.layoutHeaderView(size.width)
}

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
    self.layoutHeaderView(self.tableView.bounds.width)
}

func layoutTableHeaderView(width: CGFloat) {
    let view = UIView(frame: CGRect(x: 0, y: 0, width: width, height: 0))
    view.setTranslatesAutoresizingMaskIntoConstraints(false)

    // [add subviews and their constraints to view]

    let widthConstraint = NSLayoutConstraint(item: view, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: width)

    view.addConstraint(widthConstraint)
    let height = view.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize).height
    view.removeConstraint(constraint)

    view.frame = CGRect(x: 0, y: 0, width: width, height: height)
    view.setTranslatesAutoresizingMaskIntoConstraints(true)

    self.tableView.tableHeaderView = view
}