Get rid of subview if collection view is empty - ios

Question

I have a collection view when I display a message to the user if the collection view is empty. I also programmatically add a button to let the user add a photo if the collection view is empty. However, once the photo is added and the I reload the collection view, I found a way to get rid of the label, however, how can I get rid of the button's subview? since I can't access "self.collectionViews?.addSubview(button)" since it is in a guard let statement. Thanks in advance!
guard let parseUSERS = parseJSON["users"] as? [AnyObject] else {
// if the collection view is empty, display a message
let messageLabel = UILabel(frame: CGRect(x: 20.0, y: 10, width: self.collectionViews!.bounds.size.width - 40.0, height: (self.collectionViews?.bounds.size.height)!))
messageLabel.text = "Collection view is empty!"
messageLabel.font = messageLabel.font.withSize(20)
messageLabel.font = UIFont.boldSystemFont(ofSize: messageLabel.font.pointSize)
messageLabel.textColor = UIColor.white
messageLabel.numberOfLines = 0
messageLabel.textAlignment = NSTextAlignment.center
messageLabel.sizeToFit()
let button = UIButton(frame: CGRect(x: 80.0, y: 320, width: 215, height: 50))
button.backgroundColor = UIColor.white
button.setTitle("create",for: .normal)
button.setTitleColor(colorCircleBlue, for: .normal)
button.addTarget(self, action: #selector(self.action(sender:)), for: .touchUpInside)
// round corners for login/register buttons
button.layer.cornerRadius = button.bounds.width / 20
self.collectionViews?.backgroundColor = UIColor.blue
self.collectionViews?.backgroundView = messageLabel
self.collectionViews?.addSubview(button)
return
}
self.collectionViews?.backgroundColor = UIColor.white
self.collectionViews?.backgroundView = nil

Answer 1

I would recommend making a UIView that contains both your UILabel and the UIButton. Then setting the aforementioned UIView as the backgroundView of the UICollectionView. Ensure userInteraction is enabled on the backgroundView.
This will make sure that the both the UILabel & the UIButton are removed when you set the backgroundView to nil.
Something like this should do the trick (Be aware I have not tested this):
//Container view
let view = UIView.init(frame: self.collectionViews?.frame)
//Label
let messageLabel = UILabel(frame: CGRect(x: 20.0, y: 10, width: self.collectionViews!.bounds.size.width - 40.0, height: (self.collectionViews?.bounds.size.height)!))
messageLabel.text = "Collection view is empty!"
messageLabel.font = messageLabel.font.withSize(20)
messageLabel.font = UIFont.boldSystemFont(ofSize: messageLabel.font.pointSize)
messageLabel.textColor = UIColor.white
messageLabel.numberOfLines = 0
messageLabel.textAlignment = NSTextAlignment.center
messageLabel.sizeToFit()
//Button
let button = UIButton(frame: CGRect(x: 80.0, y: 320, width: 215, height: 50))
button.backgroundColor = UIColor.white
button.setTitle("create",for: .normal)
button.setTitleColor(colorCircleBlue, for: .normal)
button.addTarget(self, action: #selector(self.action(sender:)), for: .touchUpInside)
// round corners for login/register buttons
button.layer.cornerRadius = button.bounds.width / 20
//Add elements to container view
view.addSubview(messageLabel)
view.addSubview(button)
self.collectionViews?.backgroundView = view
Then in the future when you want to remove both elements you can just set the backgroundView to nil.