Update UILabel inside UITableViewCell without full page refresh using Swift - ios

Question

I have a particular conundrum where I need a specific UILabel inside a UITableViewCell to update every minute. Currently, every minute, the whole entire cell refreshes and displays beneath the previous one, see below, all I want to do is refresh that UILabel called watchTime:
Here's my tableView where I initialize the watch time minute count from the model
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "watchTimeCell", for: indexPath) as! WatchTimeCell
if userModel.count > indexPath.row {
//this is the value i want to update
cell.watchTime.text = "\(String(describing: userModel[indexPath.row].watchTime!))"
}
return cell
}
And here's how I update my cell currently:
#objc func updateCounting(){
watchTime += 1
if watchTime % 60 == 0 {
let userRef = Database.database().reference().child("users").child(uid!).child("watchTime")
userRef.runTransactionBlock({ (currentData: MutableData) -> TransactionResult in
let newValue: Int
if let existingValue = (currentData.value as? NSNumber)?.intValue {
newValue = existingValue + 1
} else {
newValue = 1
}
currentData.value = NSNumber(value: newValue)
//this is the line where I reload the cell
DispatchQueue.main.async(execute: {
self.watchTableView.reloadData()
})
return TransactionResult.success(withValue: currentData)
})
watchTime = 0
}
}
What's the best way to go about this? Thanks!
EDIT: Added numberOfRowsInSection
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return userModel.count
}

Answer 1

What you're doing is essentially correct for a table view. You update the model and call reload to propagate that thru cellForRowAt to the table view. You could, in this situation, save some overhead by calling reloadRows(at:with:) so as to reload only the one cell.
Except...
You have only one cell. But a one-cell table view is ridiculous. What's its purpose? To make the interface scrollable? Then just make a scroll view. Now you can update the label directly.

Answer 2

I would create that one cell, with a reference to it in the ViewController that is holding the tableView.
let mainCell = WatchTimeCell()
Inside the WatchTimeCell class I would add a public func to update the time count
public func updateTimeCountLabel(_ count: Int) {
self.nameOfLabel.text = "\(count)"
}
Then within the updateCounting() I would call the updateTimeCountLabel inside the WatchTimeCell.
self.mainCell.updateTimeCountLabel(newValue)
But there is something happening within the numberOfRowsForSection, could you post that?