refreshing table while scrolling ios swift - ios

Question

I have tableView with custom cell. I load some information from the internet and add it to the table if user scroll table down. Problem: after loading information new cells sometimes rewrite old cells, and sometimes blank cells appears in this table while scrolling. There is my code:
var Bool canEdit = true
#IBOutlet var table : UITableView!
var eventList : [EventCell] = [] // EventCell - custom cell class
func addEventsAndRefresh() {
if (canEdit){
canEdit = false
HTTPManager.getEvents(isFuture: true, offset: eventList.count, didLoad: getEvents) //it creates url and call function "getEvents" after ending async request
}
}
func getEvents(response : NSURLResponse!, data : NSData!, error : NSError!) {
if ((error) != nil) {
HTTPManager.showErrorAlert()
} else {
var result = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSArray
for elementOfArray in result {
var cell : EventCell = table.dequeueReusableCellWithIdentifier("EventCell") as EventCell
... // parsing result to cell
eventList.append(cell)
}
table.reloadData()
canEdit = true
}
}
func tableView(tableView: UITableView!, numberOfRowsInSection section: Int) -> Int {
return eventList.count
}
func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
return eventList[indexPath.row]
}
func scrollViewDidEndDragging(scrollView: UIScrollView!, willDecelerate decelerate: Bool) {
var currentOffset = scrollView.contentOffset.y;
var maximumOffset = scrollView.contentSize.height - scrollView.frame.size.height;
if (maximumOffset - currentOffset <= -40.0 && canEdit) {
addEventsAndRefresh()
}
}

Answer 1

I got the same problem when I reused the cell variable as you do.
Try to not put your cells in a list but instead save your result list as an instance variable and get the objects by in index in cellForRowAtIndexPath function as shown below.
func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell! {
var cell : EventCell = table.dequeueReusableCellWithIdentifier("EventCell") as EventCell
var element = result[indexPath.row] as YourObject
//Do something with cell
return cell
}