Referencing superview inside of view code class file - ios

Question

I'm currently trying to learn constraints and styling programmatically in Swift. I'm also trying to maintain clean and modularized code by splitting up code that relates to "styling".
I simply have my LoginViewController:
import UIKit
class LoginViewController: UIViewController {
var loginView: LoginView!
override func viewDidLoad() {
super.viewDidLoad()
loginView = LoginView(frame: CGRect.zero)
self.view.addSubview(loginView)
// AutoLayout
loginView.autoPinEdgesToSuperviewEdges(with: UIEdgeInsets.zero, excludingEdge: .bottom)
}
override var preferredStatusBarStyle: UIStatusBarStyle {
return .lightContent
}
}
Then my LoginView:
import UIKit
class LoginView: UIView {
var shouldSetupConstraints = true
var headerContainerView: UIView!
override init(frame: CGRect) {
super.init(frame: frame)
// Header Container View
headerContainerView = UIView(frame: CGRect.zero)
headerContainerView.backgroundColor = UIColor(red:0.42, green:0.56, blue:0.14, alpha:1.0) // #6B8E23
headerContainerView.translatesAutoresizingMaskIntoConstraints = false
self.addSubview(headerContainerView)
headerContainerView.topAnchor.constraint(equalTo: self.superview!.topAnchor)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override func updateConstraints() {
if(shouldSetupConstraints) {
// AutoLayout constraints
shouldSetupConstraints = false
}
super.updateConstraints()
}
}
Where I am getting stuck is with just simply trying to add this headerContainerView to the top of my superview. I want to be able to add it so it pins itself to the top, left and right of the superview and only 1/3 of the superview's height. I continue to try and reference the superview with no success and I cannot find a solution that helps me understand on the internet. Any suggestions on how I can complete this?
Thank you for taking the time for those that respond.
NOTE: I did start out using PureLayout which is really nice. However, I am an individual that likes to understand what is going on behind the scenes or at least how to write the code at its base level. You can see that I am using a PureLayout function in my LoginViewController, but I am looking to change that. I would prefer a solution that doesn't add a third party library.

Answer 1

Here self in the custom UIView class is the parent view of headerContainerView so , You can add this , Also I recommend to learn constraints first without 3rd party libraries to fully understand the concept as you will learn a lot from seeing conflicts and other things , once done , shift to libraries
override init(frame: CGRect) {
super.init(frame: frame)
// Header Container View
headerContainerView = UIView(frame: CGRect.zero)
headerContainerView.backgroundColor = UIColor(red:0.42, green:0.56, blue:0.14, alpha:1.0) // #6B8E23
headerContainerView.translatesAutoresizingMaskIntoConstraints = false
self.addSubview(headerContainerView)
headerContainerView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
headerContainerView.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
headerContainerView.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
headerContainerView.heightAnchor.constraintEqualToAnchor(self.heightAnchor, multiplier:1.0/3.0, constant: 0.0).active = true
}
// loginView layout
override func viewDidLoad() {
super.viewDidLoad()
loginView = LoginView(frame: CGRect.zero)
self.view.addSubview(loginView)
loginView.translatesAutoresizingMaskIntoConstraints = false
loginView.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
loginView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor).isActive = true
loginView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor).isActive = true
loginView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor).isActive = true

Answer 2

headerContainerView.snp.makeConstraints { (make) in
make.top.equalTo(self)
make.leading.and.trailing.equalTo(self)
make.height.equalTo(self.frame.height/3)
}
With SnapKit.

Answer 3

With SnapKit, you can do the following:
override func viewDidLoad() {
super.viewDidLoad()
loginView = LoginView(frame: CGRect.zero)
self.view.addSubview(loginView)
// AutoLayout
loginView.snp.makeConstraints { (make) in
make.left.equalTo(view.snp.left)
make.right.equalTo(view.snp.right)
make.top.equalTo(view.snp.top)
make.height.equalTo(view.snp.height).multipliedBy(1/3)
}
}