UICollectionViewDelegateFlowLayout methods never called - ios

Question

I have a UICollectionView which lies upon a UITableViewCell. The cell is the delegate and datasource for the collection view. Everything is setup in a storyboard. The cell implements numberOfItemsInSection and cellForItemAtIndexPath methods and these methods are always called successfully. Also the cell implements methods from UICollectionViewDelegateFlowLayout protocol such as sizeForItemAtIndexPath. And these methods are never called. What may be a possible reason for that?
class SignUpFollowCategoriesCell : UITableViewCell, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout
{
#IBOutlet weak var categoryCollection: UICollectionView!
#IBOutlet weak var categoryLabel: UILabel!
#IBOutlet weak var followButton: UIButton!
func setChosen(chosen:Bool)
{
followButton.checked = chosen
}
var category:Category?
{
didSet
{
guard let confirmedFollowButton = self.followButton else
{
return
}
confirmedFollowButton.hidden = true
guard let category = self.category else
{
return
}
guard let controller = self.controller else
{
return
}
guard let sites = controller.allSites[category.id] else
{
return
}
confirmedFollowButton.hidden = sites.count == 0
}
}
weak var controller:SignUpFollowCategoriesController?
func setupWithController(control:SignUpFollowCategoriesController)
{
controller = control
guard let tmp = followButton else
{
return
}
tmp.addTarget(self, action: #selector(SignUpFollowCategoriesCell.clicked), forControlEvents: .TouchUpInside)
followButton.setStyleOptions(false, style: .ClearBackground, title: "+ Follow All")
followButton.setStyleOptions(true, style: .YellowBackground, title: "Following")
}
func clicked()
{
guard let control = controller else
{
return
}
guard let cat = category else
{
return
}
if control.categoryIsChosen(cat)
{
self.setChosen(false)
control.unfollowCategory(cat)
}else
{
self.setChosen(true)
control.followCategory(cat)
}
categoryCollection.reloadData()
}
private func updateFollowBtnStyle()
{
guard let control = controller else
{
return
}
guard let cat = category else
{
return
}
if control.categoryIsChosen(cat)
{
self.setChosen(true)
}else
{
self.setChosen(false)
}
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
if let tmp = self.category
{
if let sites = controller?.allSites[tmp.id]
{
return sites.count
}
}
return 0;
}
private func firstLetterCaps(str : String) -> String
{
var ret = str
ret.replaceRange(str.startIndex...str.startIndex, with: String(str[str.startIndex]).capitalizedString)
return ret
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell
{
if let cell:SignupCategorySiteCell = collectionView.dequeueReusableCellWithReuseIdentifier("SignUpCategoryCollectionCell", forIndexPath: indexPath) as? SignupCategorySiteCell
{
cell.imageView.image = UIImage.imageWithColor(UIColor.slangBlueLight())
var slangSite : SlangSite?
if let tmpID = self.category?.id
{
let sites = controller?.allSites[tmpID]
if let site = sites![indexPath.row] as SlangSite?
{
if let url = site.details.siteProfileImageURL()
{
cell.imageView.af_setImageWithURL(url)
}
let siteName = firstLetterCaps(site.details.siteName)
cell.siteNameLabel.text = siteName
slangSite = site
}
}
if let control = controller,let site = slangSite
{
if control.siteIsChosen(site)
{
cell.followStyle()
}
else
{
cell.unfollowStyle()
}
}
cell.onCellClickedBlock = {[weak self,controller] in
if let site = slangSite, let control = controller
{
if control.siteIsChosen(site)
{
cell.unfollowStyle()
control.unfollowSite(site)
}
else
{
cell.followStyle()
control.followSite(site)
}
self?.updateFollowBtnStyle()
}
}
return cell
} else
{
collectionView.registerClass(UICollectionViewCell.self, forCellWithReuseIdentifier: "DebugCell")
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("DebugCell", forIndexPath: indexPath)
cell.backgroundColor = UIColor.greenColor()
return cell
}
}
func collectionView(collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: NSIndexPath) -> CGSize
{
return CGSizeMake(92, 112)
}
func collectionView( collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsetsZero
}
func collectionView( collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 100.0
}
}

Answer 1

Check method name according to the swift version:
public func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize
=======> sizeForItemAtIndexPath