Add to ContainerViews in a loop - swift

Question

I want to use containerviews to contain three instances of a collectionview.
My outlets are:
#IBOutlet weak var topContainer: UIView!
#IBOutlet weak var middleContainer: UIView!
#IBOutlet weak var bottomContainer: UIView!
I can do it: with a disgusting solution with repeating code in viewdidload:
topContainer.translatesAutoresizingMaskIntoConstraints = false
middleContainer.translatesAutoresizingMaskIntoConstraints = false
bottomContainer.translatesAutoresizingMaskIntoConstraints = false
// add child view controller view to container
if let controller = storyboard!.instantiateViewController(withIdentifier: "collectionscroll") as? CollectionScrollViewController {
addChild(controller)
controller.view.translatesAutoresizingMaskIntoConstraints = false
topContainer.addSubview(controller.view)
NSLayoutConstraint.activate([
controller.view.leadingAnchor.constraint(equalTo: topContainer.leadingAnchor),
controller.view.trailingAnchor.constraint(equalTo: topContainer.trailingAnchor),
controller.view.topAnchor.constraint(equalTo: topContainer.topAnchor),
controller.view.bottomAnchor.constraint(equalTo: topContainer.bottomAnchor)
])
controller.didMove(toParent: self)
}
if let controller = storyboard!.instantiateViewController(withIdentifier: "collectionscroll") as? CollectionScrollViewController {
addChild(controller)
controller.view.translatesAutoresizingMaskIntoConstraints = false
middleContainer.addSubview(controller.view)
NSLayoutConstraint.activate([
controller.view.leadingAnchor.constraint(equalTo: middleContainer.leadingAnchor),
controller.view.trailingAnchor.constraint(equalTo: middleContainer.trailingAnchor),
controller.view.topAnchor.constraint(equalTo: middleContainer.topAnchor),
controller.view.bottomAnchor.constraint(equalTo: middleContainer.bottomAnchor)
])
controller.didMove(toParent: self)
}
if let controller = storyboard!.instantiateViewController(withIdentifier: "collectionscroll") as? CollectionScrollViewController {
addChild(controller)
controller.view.translatesAutoresizingMaskIntoConstraints = false
bottomContainer.addSubview(controller.view)
NSLayoutConstraint.activate([
controller.view.leadingAnchor.constraint(equalTo: bottomContainer.leadingAnchor),
controller.view.trailingAnchor.constraint(equalTo: bottomContainer.trailingAnchor),
controller.view.topAnchor.constraint(equalTo: bottomContainer.topAnchor),
controller.view.bottomAnchor.constraint(equalTo: bottomContainer.bottomAnchor)
])
controller.didMove(toParent: self)
}
So to cut out repeating code I think of using a looop:
lazy var containers : [UIView] = [topContainer, middleContainer, bottomContainer]
for container in containers {
container.translatesAutoresizingMaskIntoConstraints = false
if let controller = storyboard!.instantiateViewController(withIdentifier: "collectionscroll") as? CollectionScrollViewController {
addChild(controller)
controller.view.translatesAutoresizingMaskIntoConstraints = false
topContainer.addSubview(controller.view)
NSLayoutConstraint.activate([
controller.view.leadingAnchor.constraint(equalTo: container.leadingAnchor),
controller.view.trailingAnchor.constraint(equalTo: container.trailingAnchor),
controller.view.topAnchor.constraint(equalTo: container.topAnchor),
controller.view.bottomAnchor.constraint(equalTo: container.bottomAnchor)
])
controller.didMove(toParent: self)
}
}
Yet it doesn't work - the middle view does not populate and the last one does not scroll.
How can I populate my containers without copy pasta codez?

Answer 1

I see one error. When you transformed the code by adding the loop, you forgot to change one of the topContainers to container.
Change:
topContainer.addSubview(controller.view)
to:
container.addSubview(controller.view)