ios swift : How can i delay cell to appear in a tableview?

Question

I have uitableview and I wanna make cells show one after one that's gonna after number of seconds

I have tried sleep(2) and dispatchafter inside of cellForRowAtIndexPath method but neither works

I just want that returned cell to wait number of seconds. Here's the code :

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell")! as! CustomCell

    cell.chatText.text = self.texts[indexPath.row]
    cell.textLabel?.textColor = UIColor.whiteColor()
    cell.backgroundColor = UIColor.clearColor()
    sleep(4)
    return cell
}

Any idea ?

Answer 1

In cellForRow method add this code :

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell")! as! CustomCell

    cell.chatText.text = self.texts[indexPath.row]
    cell.textLabel?.textColor = UIColor.whiteColor()
    cell.backgroundColor = UIColor.clearColor()

    let delay = 0.55 + Double(indexPath.row) * 0.5; //calculate delay
    print(delay) // print for sure

    UIView.animateWithDuration(0.2, delay: delay, options: .CurveEaseIn, animations: {
        cell.alpha = 1.0 // do animation after delay
    }, completion: nil)

    return cell
}

You have to set up more and more delay for each cell to see animation and display one cell after another

Hope it help you

Answer 2

In Swift 2.1+, this should get you an animated insertion of a cell to your tableView. I'd put the dispatch_after in your viewDidAppear or viewDidLoad of your UITableViewController or UIViewController that contains the tableView.

let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC)))
dispatch_after(delayTime, dispatch_get_main_queue()) {
tableView.beginUpdates()
tableView.insertRowsAtIndexPaths([YourIndexPathYouWantToInsertTo], withRowAnimation: .Fade)
tableView.endUpdates()
}

And to create an NSIndexPath:

NSIndexPath(forRow: 0, inSection: 0)