Vfrdtyky

Hi I have a problem with UI in my app, I make a closure UITableView so it will display half of my screen and set a tableView delegate and dataSource in viewDidLoad. but my UI is load very slow, I try to use DispatchQueue in my request but nothing works. and try DispatchQueue.global(qos: .background).async in tableView delegate and datasource, the UI show up and table view being display but there is a warning say tableView delegate and dataSource main run in main thread. But the object load slow too. can anyone suggest what should I do?

this is my code

let tableView: UITableView = {

    let view = UITableView()

    view.backgroundColor = .white

    view.layer.cornerRadius = 20

    return view

}()

this is my function and called in viewDidLoad

fileprivate func setupTableView() {

    DispatchQueue.main.async {

        self.tableView.delegate = self

        self.tableView.dataSource = self

        self.tableView.register(PrayerTimeViewCell.self, forCellReuseIdentifier: self.cellId)

        self.tableView.separatorColor = .clear

        self.tableView.backgroundColor = .clear

        self.tableView.rowHeight = 53

    }

}

this is my request code

DispatchQueue.global(qos: .background).async {

            Alamofire.request(prayerUrl, method: .get, parameters: nil, encoding: URLEncoding.default, headers: nil).responseData(completionHandler: { (dataResponse) in

                if let err = dataResponse.error {

                    print("Failed to fetch data:", err)

                    return

                }



                guard let data = dataResponse.data else { return }



                do {

                    let prayerData = try JSONDecoder().decode(PrayerModel.self, from: data)



                    prayerData.items.forEach({ (item) in

                        let shubuh = Prayer(prayerName: "Shubuh", prayerIcon: #imageLiteral(resourceName: "PartlyCloudyNight"), prayerTime: item.fajr)

                        let dzuhur = Prayer(prayerName: "Dzuhur", prayerIcon: #imageLiteral(resourceName: "Sunny"), prayerTime: item.dhuhr)

                        let ashar = Prayer(prayerName: "Ashar", prayerIcon: #imageLiteral(resourceName: "PartlyCloudyDay"), prayerTime: item.asr)

                        let maghrib = Prayer(prayerName: "Maghrib", prayerIcon: #imageLiteral(resourceName: "Overcast"), prayerTime: item.maghrib)

                        let isya = Prayer(prayerName: "Isya", prayerIcon: #imageLiteral(resourceName: "Clear"), prayerTime: item.isha)

                        self.prayers.append(contentsOf: [shubuh, dzuhur, ashar, maghrib, isya])

                    })

                    DispatchQueue.main.async {

                        self.tableView.reloadData()

                    }

                } catch let decodeErr {

                    print("Failed to decode:", decodeErr)

                }

            })

        }

It takes some time than you get data from http request, so your table view will be without data until http request isn't completed. In this case I suggest writing code without any DispatchQueue.main.async etc.

Just write this to your viewDidLoad function:

override func viewDidLoad() {

    super.viewDidLoad()

    tableView.delegate = self

    tableView.dataSource = self

    tableView.register(PrayerTimeViewCell.self, forCellReuseIdentifier: cellId)

    tableView.separatorColor = .clear

    tableView.backgroundColor = .clear

    tableView.rowHeight = 53



    getPrayersData() // this is moment when you probably haven't got data yet

}

Now create function for getPrayerData()

func getPrayersData() {

    Alamofire.request(prayerUrl, method: .get).responseJSON { response in



        // this is moment when request is completed



        guard let data = response.data else {

            print("Failed to fetch data:", response.error)

            return 

        }



        do {

            let prayerData = try JSONDecoder().decode(PrayerModel.self, from: data)



            prayerData.items.forEach({ (item) in

                let shubuh = Prayer(prayerName: "Shubuh", prayerIcon: #imageLiteral(resourceName: "PartlyCloudyNight"), prayerTime: item.fajr)

                let dzuhur = Prayer(prayerName: "Dzuhur", prayerIcon: #imageLiteral(resourceName: "Sunny"), prayerTime: item.dhuhr)

                let ashar = Prayer(prayerName: "Ashar", prayerIcon: #imageLiteral(resourceName: "PartlyCloudyDay"), prayerTime: item.asr)

                let maghrib = Prayer(prayerName: "Maghrib", prayerIcon: #imageLiteral(resourceName: "Overcast"), prayerTime: item.maghrib)

                let isya = Prayer(prayerName: "Isya", prayerIcon: #imageLiteral(resourceName: "Clear"), prayerTime: item.isha)

                self.prayers.append(contentsOf: [shubuh, dzuhur, ashar, maghrib, isya])

            })



            self.tableView.reloadData()



        } catch {

            print("Failed to decode: (error)")

        }

    }

}