Clash Royale CLAN TAG#URR8PPP

how to make table view shows specific row after reloading the data in swift?

I am trying to implement pagination in table view. so when fetching data from server, I want to get 10 data per request.

so the first time user opens the view, it will fetch 10 data, after the user scrolls to the 10th row, it will send request to get the data 11st to 20th.

but after fetching that 11-20th data and reloading the table view, it seems the table view drag down and it shows the last row (i.e the 20th row).

I want after the 10th row --> fetching data --> show the 11st row of the table view

so it will give smooth scrolling and good user experience

here is the simplified code i use. Thanks in advance

let numberOfDocumentsPerQuery = 5
var fetchingMore = false
var recommendedEventList = [EventKM]()
var lastDocumentFromQuery : QueryDocumentSnapshot?

extension HomeVC : UITableViewDelegate, UITableViewDataSource
//MARK: - Table View Methods

func numberOfSections(in tableView: UITableView) -> Int
return 1


func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
return recommendedEventList.count


func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
let cell = tableView.dequeueReusableCell(withIdentifier: "HomeCell", for: indexPath) as! HomeCell
cell.eventData = recommendedEventList[indexPath.row]
return cell



func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool)

// to fetch more events if it comes to the bottom of table view

let currentOffset = scrollView.contentOffset.y
let maximumOffset = scrollView.contentSize.height - scrollView.frame.size.height

if maximumOffset - currentOffset <= 10.0
if !fetchingMore
getRecommendedEvents()




func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath)
performSegue(withIdentifier: "toEventDetailVC", sender: nil)




func getRecommendedEventsFromBeginning()

EventKM.observeRecommendedEvents (

selectedCity: selectedCity,
limit: numberOfDocumentsPerQuery) (recommendedList, listener, lastDocument) in

if let events = recommendedList
self.recommendedEventList = events
self.tableView.reloadData()

self.lastDocumentFromQuery = lastDocument
self.recommendedListener = listener
self.fetchingMore = false

else
self.fetchingMore = true // to stop fetching data








2 Answers
2

You can have a property to record the row that scroll to.
var rowForScroll = 1

var rowForScroll = 1

every time you loaded data, add the rowForScroll

rowForScroll

rowForScroll = rowForScroll + 10
let ip = NSIndexPath(forRow: rowForScroll, inSection: 0)
self.tableView.scrollToRowAtIndexPath(ip, atScrollPosition: .bottom, animated: true)


// Add your custom object.
recommendedEventList.add(customObject)

let numberOfRowsBeforeAPIRequest = tableView.numberOfRows(inSection: section)
let indexPath:IndexPath = IndexPath(row:(recommendedEventList.count - 1), section:0)
tableView.insertRows(at:[indexPath], with: .none)

// Do Validate if the actual indexpath exists or not, else will crash.
let ip = NSIndexPath(forRow: numberOfRowsBeforeAPIRequest + 1, inSection: 0)

tableView.scrollToRowAtIndexPath(ip, atScrollPosition: .bottom, animated: true)


Just putting what I am trying to do above.

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