Uitableview infinite scroll hang lag - swift

Question

view the video of problem here
Im trying to make my infinite scroll work smoothly, before i had it working in a way where when the user reachs a certain item count in the table, it would load the others but while doing the load a Footer Activity indicator would appear, then dissapear and add the next batch of rows... which i kinda found annoying later on.. so i wanned to opmitized it. i want the tableview to initially load 100 items, then when the user is just around row 10 it would start to load the next 100 items and rows... the thing is.. everytime it makes the call.. the uitableview kinda hangs...
I did eliminate some trivial code here like the segmented control and letter buttons.. etc,
//
// VCrestlist.swift
// AsyncUITableview
import UIKit
import Foundation
import Alamofire
import SwiftyJSON
import Parse
class VCrestlist: UITableViewController{
let PageSize = 80
var items:[RestsModel] = []
var isLoading = false
var letter = "ALL"
var online = false
var loaded = false
var bigviewforact:UIView = UIView(frame: UIScreen.main.bounds)
#IBOutlet var MyFooterView : UIView!
override func viewDidLoad() {
super.viewDidLoad()
self.MyFooterView.isHidden = true
createButtons()
// Load custom Xib RestCell
let nib = UINib(nibName: "RestCell", bundle: nil)
// register cell identifier with custom Xib RestCell
self.tableView.register(nib, forCellReuseIdentifier: "Cell")
tableView.dataSource = self
loadSegment(0, size: self.PageSize,argletter:"ALL",online:self.online)
self.ButtonsScrollView.isScrollEnabled = true
}
class DataManager {
func requestData(_ offset:Int, size:Int,letter:String,online:Bool, listener:#escaping ([RestsModel]) -> ()) {
DispatchQueue.global(qos: .background).async {
var letra = ""
print("el offest es \(offset) y el size es \(size)")
if (letter != "") {
letra = letter
} else {
letra = "ALL"
}
let cart = Cart.sharedInstance
Alamofire.request("https://www.getmedata.com/rests.php", parameters: ["offset": "\(offset)","size":"\(size)","letra":"\(letra)","online":"\(online)"]).authenticate(usingCredential: cart.credential).responseJSON() {
response in
if(response.result.value != nil) {
let jsonObj = JSON(response.result.value!);
let rests = jsonObj as JSON
// print(jsonObj);
//generate items
if let restsarray = rests["rests"].arrayValue as [JSON]? {
var arr = [RestsModel]()
//3
for restDict in restsarray {
let restName: String? = restDict["nombre"].stringValue
let restLOGO: String? = restDict["logo"].stringValue
let detURL: String? = restDict["url"].stringValue
let detProvincia: String? = restDict["provincia"].stringValue
let detHorario: String? = restDict["horario"].stringValue
let detDireccion: String? = restDict["direccion"].stringValue
let detTipoComida: String? = restDict["tipo_comida"].stringValue
let detTelefono: String? = restDict["telefono"].stringValue
let detidRest: String? = restDict["id"].stringValue
let detalleDelivery: String? = restDict["alldelivery"].stringValue
let detalleOrderOnline: String? = restDict["orderonline"].stringValue
let detalleReservaOnline: String? = restDict["reservasonline"].stringValue
let dethasSchedule: Bool? = restDict["hasSchedule"].boolValue
let detopenNow: Bool? = restDict["opennow"].boolValue
let detscheduleToday: String? = restDict["scheduleToday"].stringValue
let detscheduleTodayLiteral: String? = restDict["scheduleTodayLiteral"].stringValue
let emp_instagram: String? = restDict["emp_instagram"].stringValue
let emp_e_orderonline: String? = restDict["emp_e_orderonline"].stringValue
let emp_e_reservasonline: String? = restDict["emp_e_reservasonline"].stringValue
let emp_e_kids: String? = restDict["emp_e_kids"].stringValue
let emp_e_pickup: String? = restDict["emp_e_pickup"].stringValue
let emp_e_delivery: String? = restDict["emp_e_delivery"].stringValue
let emp_e_wifi: String? = restDict["emp_e_wifi"].stringValue
let emp_e_valet: String? = restDict["emp_e_valet"].stringValue
let emp_e_exterior: String? = restDict["emp_e_exterior"].stringValue
let emp_e_happyhour: String? = restDict["emp_e_happyhour"].stringValue
let emp_e_desayuno: String? = restDict["emp_e_desayuno"].stringValue
let emp_e_fumar: String? = restDict["emp_e_fumar"].stringValue
let emp_e_vinos: String? = restDict["emp_e_vinos"].stringValue
let emp_e_bar: String? = restDict["emp_e_bar"].stringValue
let emp_e_games: String? = restDict["emp_e_games"].stringValue
let rest = RestsModel(name: restName!,image:restLOGO!,detailURL:detURL!,provincia:detProvincia!,tipocomida:detTipoComida!,idRest:detidRest!,hasSchedule: dethasSchedule!,scheduleToday: detscheduleToday!,scheduleTodayLiteral: detscheduleTodayLiteral!,openNow: detopenNow!,allDelivery: detalleDelivery!,orderonline: detalleOrderOnline!,reservaonline: detalleReservaOnline!, instagram: emp_instagram!, emp_e_kids: emp_e_kids!, emp_e_pickup: emp_e_pickup!, emp_e_delivery: emp_e_delivery!, emp_e_wifi: emp_e_wifi!, emp_e_valet: emp_e_valet!, emp_e_exterior: emp_e_exterior!, emp_e_happyhour: emp_e_happyhour!, emp_e_desayuno: emp_e_desayuno!, emp_e_fumar: emp_e_fumar!, emp_e_vinos: emp_e_vinos!, emp_e_bar: emp_e_bar!, emp_e_games: emp_e_games!, horario: detHorario!, direccion: detDireccion! ,telefono: detTelefono!)
arr.append(rest)
}
print(arr)
//call listener in main thread
DispatchQueue.main.async {
listener(arr)
}
}
}
}
}
///
}
}
func loadSegment(_ offset:Int, size:Int,argletter:String,online:Bool) {
if (self.loaded == false) {
let act:UIActivityIndicatorView = UIActivityIndicatorView(activityIndicatorStyle: UIActivityIndicatorViewStyle.gray)
bigviewforact.addSubview(act)
act.center = bigviewforact.center
self.view.addSubview(bigviewforact)
self.view.bringSubview(toFront: bigviewforact)
act.hidesWhenStopped = true
act.startAnimating()
//self.bigviewforact.removeFromSuperview()
self.loaded = true
}
//if (!self.isLoading) {
// self.isLoading = true
//self.MyFooterView.isHidden = (offset==0) ? true : false
let manager = DataManager()
manager.requestData(offset, size: size,letter:argletter,online:online,
listener: {(items:[RestsModel]) -> () in
/*
Add Rows at indexpath
*/
for item in items {
self.tableView.beginUpdates()
let row = self.items.count
let indexPath = IndexPath(row:row,section:0)
self.items += [item]
self.tableView?.insertRows(at: [indexPath], with: UITableViewRowAnimation.fade)
self.tableView.endUpdates()
}
self.bigviewforact.removeFromSuperview()
self.isLoading = false
self.MyFooterView.isHidden = true
}
)
// }
}
override func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
if indexPath.row == items.count-70 {
loadSegment(items.count, size: PageSize,argletter:self.letter,online:self.online)
}
}
// MARK: Table view data source
override func numberOfSections(in tableView: UITableView?) -> Int {
return 1
}
override func tableView(_ tableView: UITableView?, numberOfRowsInSection section: Int) -> Int {
return items.count
}
override func tableView(_ tableView: UITableView?, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 85;
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell : RestCell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! RestCell
// Pass data to Cell :) clean the mess at the View Controller ;)
cell.restData = items[indexPath.row]
cell.tag = indexPath.row
return cell
}
}

Answer 1

Don't insert each item into UITableView. Insert all of them together.
var indexPathes: [IndexPath] = []
var newItems: [RestsModel] = []
for item in items {
let row = self.items.count
let indexPath = IndexPath(row:row,section:0)
newItems.append(item)
indexPathes.append(indexPath)
}
self.items.append(contentsOf: newItems)
self.tableView.beginUpdates()
self.tableView?.insertRows(at: indexPathes, with: UITableViewRowAnimation.fade)
self.tableView.endUpdates()