Creating and Setting title of UIButton in FOR loop breaks loop - ios

Question

In my app I'm creating a paged slider (UISlider + UIPageControl). The app reaches out to CoreData to get the array of Entities to create a "page" for.
I build the paginated scroller n the following loop:
for i in 0..<features.count {
var pageWidth = Int(view.frame.width)*i
var pageView = UIView(frame: CGRectMake(CGFloat(pageWidth), 0, scrollView.frame.width, scrollView.frame.height))
pageView.backgroundColor = UIColor.clearColor()
pageView.clipsToBounds = true
//Background image
var imageView = UIImageView(frame: CGRectMake(0, 0, scrollView.frame.width, scrollView.frame.height))
var image:UIImage!
imageView.contentMode = .ScaleAspectFill
pageView.addSubview(imageView)
if fileManager.fileExistsAtPath(features[i].coverImage){
//The background image
image = UIImage(contentsOfFile: self.features[i].coverImage)
imageView.image = image
}
else if !fileManager.fileExistsAtPath(features[i].coverImage) && !features[i].coverImage.isEmpty {
FileStoreClient.downloadFileIfNotExists(features[i].cover, completion: { (success, error) -> Void in
if error == nil {
image = UIImage(contentsOfFile: self.features[i].coverImage)
imageView.image = image
}
else {
println("There was an error during the download")
}
})
}
//The background cover
var coverView = UIView(frame: CGRectMake(0, 0, view.frame.width, 250))
coverView.backgroundColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.6)
pageView.addSubview(coverView)
//The title
var titleLabel = UILabel(frame: CGRectMake(10, 40, view.frame.width-20, 25))
titleLabel.font = UIFont(name: "Haymaker", size: 24)
titleLabel.textColor = UIColor.whiteColor()
titleLabel.layer.shadowColor = UIColor.blackColor().CGColor
titleLabel.layer.shadowOffset = CGSizeMake(1, 1)
titleLabel.layer.shadowRadius = 1
titleLabel.layer.shadowOpacity = 1
titleLabel.textAlignment = .Center
titleLabel.text = features[i].title
pageView.addSubview(titleLabel)
//The text
var textLabel = UILabel(frame: CGRectMake(10, titleLabel.frame.origin.y+titleLabel.frame.height+5, view.frame.width-20, 60))
textLabel.numberOfLines = 0
textLabel.lineBreakMode = NSLineBreakMode.ByWordWrapping
textLabel.font = UIFont(name: "OpenSans", size: 13)
textLabel.textColor = UIColor.whiteColor()
textLabel.textAlignment = .Center
textLabel.text = features[i].summary
pageView.addSubview(textLabel)
//The button
var readMoreButton = UIButton(frame: CGRectMake(0, pageView.frame.height - 90, 200, 80))
readMoreButton.setAttributedTitle(NSAttributedString(string: Strings.readMoreButtonTitle, attributes: Fonts.featureButtonText), forState: UIControlState.Normal)
//readMoreButton.addTarget(self, action: "readArticle", forControlEvents: .TouchUpInside)
readMoreButton.layer.cornerRadius = 6
readMoreButton.layer.borderColor = UIColor.whiteColor().CGColor
readMoreButton.layer.borderWidth = 1
readMoreButton.center.x = pageView.center.x
pageView.addSubview(readMoreButton)
println(i)
scrollView.addSubview(pageView)
}
Everything works exactly as it should, except that the moment I try to assign a title to the new button, the loop turns into an infinite loop. If I print out the current index of the loop, it keeps cycling through endlessly. Example:
0
1
2
0
1
2
0
1
2
If I comment out the myButton.setTitle() method, the problem goes away and the indexes print out like the following:
0
1
2
I have tried setTitle and setAttributedTitle, both of which have the same effect. I have tried dispatching different queues and nothing seems to be working.
Again, everything works for the background image, the two labels, views, etc. Problem only exists when a button is brought into the mix. The issue exists even if I remove the FileStoreManager code.
Something about a button in a for loop isn't happy.
EDIT #1
I decided to try and create a new project just to test button creation in a for loop. This works perfectly fine.
var x = 20
var y = 20
override func viewDidLoad() {
super.viewDidLoad()
for i in 1...10 {
var myview = UIView(frame: CGRectMake(CGFloat(x), CGFloat(y), 100, 50))
var button = UIButton(frame: CGRectMake(0, 0, 100, 50))
button.setTitle("Test", forState: .Normal)
button.setTitleColor(UIColor.blackColor(), forState: .Normal)
button.layer.borderColor = UIColor.blackColor().CGColor
button.layer.borderWidth = 2
myview.addSubview(button)
view.addSubview(myview)
x = x+20
y = y+20
println(i)
}
}

Answer 1

You can also try fast enumeration in case something is somehow getting messed up in your range.
for feature in features { ... }
or if you need the index:
for (index, features) in features.enumerate() { ... }
Not sure it will resolve the issue, but it might increase readability.

Answer 2

It turns out it was because I had the above code in the viewDidLayoutSubviews() function. Something about setting a buttons title triggers the method, it seems.
As I needed to use this method due to dynamic sizes, I simply added a "hasLoaded:Bool" to check if the function has already fired.
This resolved the issue.