How do I set a different height for each UICollectionViewCell - ios

Question

I feel like this should be a lot easier than it is. All I want to do is have a different height for each of my collection view's cells (depending on the size of the label inside each cell). I'm using sizeForItemAtIndexPath, but the trouble is figuring out the height before the cell is created.
What I have now:
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
// target width of each cell - widht of the collectionView
let targetWidth: CGFloat = collectionView.frame.width - 20.0
// setup a prototype cell
var cell = collectionView.dequeueReusableCellWithReuseIdentifier("MyCustomCellIdentifier", forIndexPath: indexPath) as! MyCustomCell
// for the sake of simplicity, let's just assume data is coming from somewhere else
cell.nameLabel.text = data.name
cell.notesLabel.text = data.notes
// resize - layoutSubviews in LocationCell controller
cell.layoutIfNeeded()
// get the size based on constraints
var size = cell.contentView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
// force width
size.width = targetWidth
return size
}
What's not working is dequeueReusableCellWithReuseIdentifier. I'm guessing it's because the UICollectionViewCell is not yet available? I also tried registerClass to get that, but that doesn't seem to work either. :(
Is there an easier way to do this entirely? All I need to do is figure out what the height is for the cell before it's created. I need an instance of the UICollectionViewCell subclass in order to even be able to start (so I can actually access the label and try to determine a height). Been stuck on this for hours. :/

Answer 1

Use this method
func heightForComment(comment:NSString,font: UIFont, width: CGFloat) -> CGFloat {
let rect = NSString(string: comment).boundingRectWithSize(CGSize(width: width, height: CGFloat(MAXFLOAT)), options: .UsesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return ceil(rect.height)
}

Answer 2

This is not the proper way to do this, but works for me
use this function to obtain the size of the text
func labelSize(texto: NSString) -> CGRect {
var atributos = [NSFontAttributeName: UIFont.systemFontOfSize(17)]
var labelSize = texto.boundingRectWithSize(CGSizeMake(280, CGFloat(MAXFLOAT)), options: NSStringDrawingOptions.UsesLineFragmentOrigin, attributes: atributos, context: nil)
return labelSize
}