reloading visible uicollectionviewcell when nested in uitableviewcell - ios

Question

I have a UICollection that shows a padlock on cells that locked to users who aren't logged in. The user can view the collection and then login in a modal. When the modal dismisses, I am trying to reload the cells of the table and the nested collection to remove the padlocks from the cells.
The visible cells are not refreshing to remove the padlock. When the collection is scrolled, the cells offscreen are correct and show with padlock. I am calling reloaddata() on both the tableview and each nested collectionview.
The code I have is separated to:
UIViewController
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("SectionWorkouts", forIndexPath: indexPath) as! SectionTableViewCell
cell.delegate = self
// Return the workouts count from the section
let intIndex = indexPath.row
let index = workoutSections.startIndex.advancedBy(intIndex)
let currentWorkoutSectionKey = workoutSections.keys[index]
if let currentWorkoutSection = workoutSections[currentWorkoutSectionKey] {
cell.workoutsCollection.dataSource = sectionWorkoutsCell
cell.workoutsCollection.delegate = sectionWorkoutsCell
cell.updateCellWithWorkouts(currentWorkoutSectionKey, workouts: currentWorkoutSection)
}
}
return cell
}
UITableViewCell
class SectionTableViewCell: UITableViewCell,UICollectionViewDelegate, UICollectionViewDataSource {
var workouts = [Workout]()
var delegate: WorkoutCellDelegate?
#IBOutlet weak var sectionTitle: UILabel!
#IBOutlet weak var workoutsCollection: UICollectionView!
func updateCellWithWorkouts(title: String, workouts: [Workout]){
self.sectionTitle.text = title
self.workouts = workouts
dispatch_async(dispatch_get_main_queue(),{
self.workoutsCollection.reloadData()
})
}
func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
return 1
}
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("SectionWorkoutCell", forIndexPath: indexPath) as! SectionCollectionViewCell
let row = indexPath.row
let workout = workouts[row]
cell.configCell(workout)
return cell
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return workouts.count
}
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
let row = indexPath.row
let feature = workouts[row]
if let delegate = self.delegate{
delegate.didSelectWorkoutCell(feature)
}
}
}
UICollectionViewCell
class SectionCollectionViewCell: UICollectionViewCell {
#IBOutlet weak var imageContainer: UIView!
#IBOutlet weak var image: UIImageView!
#IBOutlet weak var tintOverlay: UIView!
#IBOutlet weak var padlock: UIImageView!
#IBOutlet weak var workoutTitle: UILabel!
#IBOutlet weak var duration: UILabel!
var locked = true
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
func configCell(workout: Workout){
self.workoutTitle.text = workout.name
if workout.type == "Free" || AccountManager.userIsLoggedInMember() {
self.setToUnLocked()
}else{
self.setToLocked()
}
self.layoutIfNeeded()
}
func setToUnLocked(){
locked = false
tintOverlay.alpha = 0
padlock.alpha = 0
}
func setToLocked(){
locked = true
tintOverlay.alpha = 0.6
padlock.alpha = 1
}
}

Answer 1

You should probably move the call to configure the cell to the willDisplayCell: method instead. You can remove it from the cellForItemAtIndexPath method. This is the correct time to configure any visual aspects of the cell to be displayed.
func collectionView(collectionView: UICollectionView,
willDisplayCell cell: UICollectionViewCell,
forItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let row = indexPath.row
let workout = workouts[row]
cell.configCell(workout)
return cell
}

Answer 2

The problem lies in the fact that:
the tableViewCell owns the data that is used for configuring the collectionViewCell.
If you want your collectionViewCell to update without the need for tableView.reloadData, the data that is used for configuring the collectionViewCell(in your case 'workout') must be fetched from elsewhere than from the tableViewCell.