Programmatically made constraints are not working - ios

Question

As I want to move away from xib and make my layout programmatically, I found that using the same exact constraints doesn't work as I would expect.
I want to make this UITableViewCell
It's a quite simple cell with a small icon to its right as well as an Activity Indicator so I can toggle which one I want to see. They are inside a View and to their left is a label
Those are my constraints in the outline view
And it works perfectly. However when I'm removing the XIB and doing all of the code myself, nothing works anymore
So here's my code:
class StandardRow: UITableViewCell {
private var initialWidth: CGFloat = 20
public var fetching: Bool = false {
didSet {
if (fetching) {
activityIndicator?.startAnimating()
} else {
activityIndicator?.stopAnimating()
}
changeImageWidth()
}
}
public var rightImage: UIImage? = nil {
didSet {
rightImageView?.image = rightImage
changeImageWidth()
}
}
private func changeImageWidth() {
if (activityIndicator?.isAnimating) ?? false || rightImage != nil {
imageWidth?.constant = initialWidth
} else {
imageWidth?.constant = 0
}
}
override func prepareForReuse() {
valueLabel?.text = ""
imageView?.image = nil
rightImage = nil
fetching = false
textLabel?.text = ""
accessoryType = .none
}
//Views
private var imageContainer = UIView()
private var rightImageView = UIImageView()
private var activityIndicator: UIActivityIndicatorView? = UIActivityIndicatorView()
public var valueLabel: UILabel? = UILabel()
private var imageWidth: NSLayoutConstraint? = nil
override init(style: UITableViewCell.CellStyle = .default, reuseIdentifier: String? = nil) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
buildView()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
buildView()
}
func buildView() {
contentView.addSubview(valueLabel!)
imageContainer.addSubview(rightImageView)
imageContainer.addSubview(activityIndicator!)
contentView.addSubview(imageContainer)
imageContainer.backgroundColor = .red
}
override func layoutSubviews() {
super.layoutSubviews()
//IMAGE CONTAINER CONSTRAINTS
imageWidth = NSLayoutConstraint(item: imageContainer, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: initialWidth)
imageWidth?.priority = UILayoutPriority(rawValue: 999)
imageWidth?.isActive = true
let bottomImageContainerConstraint = NSLayoutConstraint(item: imageContainer, attribute: .bottom, relatedBy: .equal, toItem: contentView, attribute: .bottom, multiplier: 1, constant: 0)
bottomImageContainerConstraint.isActive = true
bottomImageContainerConstraint.priority = UILayoutPriority(rawValue: 999)
let topImageContainerConstraint = NSLayoutConstraint(item: imageContainer, attribute: .top, relatedBy: .equal, toItem: contentView, attribute: .top, multiplier: 1, constant: 0)
topImageContainerConstraint.isActive = true
topImageContainerConstraint.priority = UILayoutPriority(rawValue: 999)
let trailingImageContainerConstraint = NSLayoutConstraint(item: imageContainer, attribute: .trailing, relatedBy: .equal, toItem: contentView, attribute: .trailing, multiplier: 1, constant: 5)
trailingImageContainerConstraint.priority = UILayoutPriority(rawValue: 999)
trailingImageContainerConstraint.isActive = true
let centerYImageContainerConstraint = NSLayoutConstraint(item: imageContainer, attribute: .centerY, relatedBy: .equal, toItem: contentView, attribute: .centerY, multiplier: 1, constant: 0)
centerYImageContainerConstraint.isActive = true
centerYImageContainerConstraint.priority = UILayoutPriority(rawValue: 999)
//VALUE LABEL CONSTRAINTS
let trailingValueLabelConstraint = NSLayoutConstraint(item: valueLabel!, attribute: .trailing, relatedBy: .equal, toItem: imageContainer, attribute: .leading, multiplier: 1, constant: 5)
trailingValueLabelConstraint.isActive = true
trailingValueLabelConstraint.priority = UILayoutPriority(rawValue: 999)
let centerYValueLabelConstraint = NSLayoutConstraint(item: valueLabel!, attribute: .centerY, relatedBy: .equal, toItem: contentView, attribute: .centerY, multiplier: 1, constant: 0)
centerYValueLabelConstraint.isActive = true
centerYValueLabelConstraint.priority = UILayoutPriority(rawValue: 999)
//ACTIVITY INDICATOR CONSTRAINGS
NSLayoutConstraint(item: activityIndicator!, attribute: .trailing, relatedBy: .equal, toItem: imageContainer, attribute: .trailing, multiplier: 1, constant: 0).isActive = true
NSLayoutConstraint(item: activityIndicator!, attribute: .leading, relatedBy: .equal, toItem: imageContainer, attribute: .leading, multiplier: 1, constant: 11).isActive = false
NSLayoutConstraint(item: activityIndicator!, attribute: .bottom, relatedBy: .equal, toItem: imageContainer, attribute: .bottom, multiplier: 1, constant: 11).isActive = false
NSLayoutConstraint(item: activityIndicator!, attribute: .top, relatedBy: .equal, toItem: imageContainer, attribute: .top, multiplier: 1, constant: 0).isActive = true
NSLayoutConstraint(item: activityIndicator!, attribute: .centerY, relatedBy: .equal, toItem: imageContainer, attribute: .centerY, multiplier: 1, constant: 0).isActive = true
//RIGHT IMAGE VIEW CONSTRAINTS
NSLayoutConstraint(item: rightImageView, attribute: .trailing, relatedBy: .equal, toItem: activityIndicator!, attribute: .trailing, multiplier: 1, constant: 0).isActive = true
NSLayoutConstraint(item: rightImageView, attribute: .leading, relatedBy: .equal, toItem: rightImageView, attribute: .leading, multiplier: 1, constant: 0).isActive = true
NSLayoutConstraint(item: rightImageView, attribute: .bottom, relatedBy: .equal, toItem: activityIndicator!, attribute: .bottom, multiplier: 1, constant: 0).isActive = true
NSLayoutConstraint(item: rightImageView, attribute: .top, relatedBy: .equal, toItem: activityIndicator!, attribute: .top, multiplier: 1, constant: 0).isActive = true
NSLayoutConstraint(item: rightImageView, attribute: .centerY, relatedBy: .equal, toItem: activityIndicator!, attribute: .centerY, multiplier: 1, constant: 0).isActive = true
//changeImageWidth()
}}
So I have a few ideas to where it can come from, firstly being "translatesAutoresizingMaskIntoConstraints" set to true by default, but when I'm setting it to false in the superview then my cell doesn't show anymore and in the contentView, Xcode tells me I shouldn't do that because of an undefined behaviour
I'm also using Reveal to debug my UI and then I found those peculiar values:
Which is not what I want, Reveal is reporting that those constraints are translating the autoresizing mask of the view to autolayout so it would confirm the previous theory. I did set the priority to 999 to some of the constraints because otherwise they would be broken.
I'm actually at a dead end and I think I'm missing something but I can't pinpoint what as I don't have enough experience with non-interface builder constraints

Answer 1

Try Anchors, it's much easier.
Example
var redView = UIView()
redView.backgroundColor = .red
anyView.addsubView(redView)
redView.translatesAutoresizingMaskIntoConstraints = false
redView.centerXAnchor.constraint(equalTo: self.parentView.centerXAnchor).isActive = true
redView.centerYAnchor.constraint(equalTo: self.parentView.centerYAnchor).isActive = true
redView.heightAnchor.constraint(equalToConstant: 100).isActive = true
redView.widthAnchor.constraint(equalToConstant: 100).isActive = true

Answer 2

You can add the same method to your UIView extension
func constrainToEdges(_ subview: UIView, top: CGFloat = 0, bottom: CGFloat = 0, leading: CGFloat = 0, trailing: CGFloat = 0) {
subview.translatesAutoresizingMaskIntoConstraints = false
let topContraint = NSLayoutConstraint(
item: subview,
attribute: .top,
relatedBy: .equal,
toItem: self,
attribute: .top,
multiplier: 1.0,
constant: top)
let bottomConstraint = NSLayoutConstraint(
item: subview,
attribute: .bottom,
relatedBy: .equal,
toItem: self,
attribute: .bottom,
multiplier: 1.0,
constant: bottom)
let leadingContraint = NSLayoutConstraint(
item: subview,
attribute: .leading,
relatedBy: .equal,
toItem: self,
attribute: .leading,
multiplier: 1.0,
constant: leading)
let trailingContraint = NSLayoutConstraint(
item: subview,
attribute: .trailing,
relatedBy: .equal,
toItem: self,
attribute: .trailing,
multiplier: 1.0,
constant: trailing)
addConstraints([
topContraint,
bottomConstraint,
leadingContraint,
trailingContraint])
}

Answer 3

I recommend using this framework for building constraint based layouts programmatically, it makes the process straightforward and faster. Take the setup for the contentView of this cell for example:
contentView.addSubview(descriptionLabel)
contentView.addSubview(amountLabel)
contentView.addSubview(dateLabel)
contentView.addSubview(bottomRightLabel)
constrain(descriptionLabel, amountLabel, dateLabel, bottomRightLabel) { desc, amount, date, bottomRight in
desc.top == desc.superview!.top + 16
desc.left == desc.superview!.left + 16
desc.right <= amount.left + 12
desc.bottom == date.top - 12
amount.centerY == desc.centerY
amount.right == amount.superview!.right - 12
date.left == date.superview!.left + 16
date.right <= bottomRight.left - 12
date.bottom == date.superview!.bottom - 16
bottomRight.centerY == date.centerY
bottomRight.right == bottomRight.superview!.right - 12
}