UITableView, cellForRowAt indexPath is not being called - ios

Question

I have been working on a launch database for SpaceX and I have successfully parsed my data but the function to create and add the data to the cell is not working. I have added the delegates and data sources but I still cannot find out why it won't run.
import UIKit
struct launchData : Decodable
{
let flight_number : Int
let launch_date_utc : String
struct rocketInfo : Decodable
{
let rocket_name : String
}
let rocket : rocketInfo
}
class LaunchViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var launchTableView: UITableView!
var arrayOfLaunchData:[launchData] = []
override func viewDidLoad()
{
super.viewDidLoad()
self.launchTableView.delegate = self
self.launchTableView.dataSource = self
getJsonData()
self.launchTableView.reloadData()
}
func getJsonData()
{
let jsonUrlString = "https://api.spacexdata.com/v2/launches"
guard let url = URL(string: jsonUrlString) else { return }
URLSession.shared.dataTask(with: url) { (data, response, err) in
guard let data = data else { return }
do {
let launchDataDecoded = try JSONDecoder().decode([launchData].self, from: data)
print(launchDataDecoded)
} catch let jsonErr {
print("Error Serialization json:", jsonErr )
}
}.resume()
print("getJsonData ran")
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print("")
print(arrayOfLaunchData.count)
print("")
print("TableView number of rows ran")
return arrayOfLaunchData.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CellID")
let launch = self.arrayOfLaunchData[indexPath.row]
let flightNumber = launch.flight_number
let rocketName = launch.rocket.rocket_name
cell?.textLabel?.text = "Mission " + String(flightNumber)
let launchDate = launch.launch_date_utc
cell!.detailTextLabel!.text = "Launch Date: " + launchDate + "Rocket Used: " + rocketName
self.launchTableView.reloadData()
print("TableView cellForRowAt ran")
return cell!
}
}

Answer 1

First of all never call reloadData() in cellForRowAt! Delete the line
Two major issues:
reloadData() is called too soon.
The data source array is not populated after receiving the data.
The solution is to delete the line
self.launchTableView.reloadData()
(also) in viewDidLoad() and change getJsonData() to
func getJsonData()
{
let jsonUrlString = "https://api.spacexdata.com/v2/launches"
guard let url = URL(string: jsonUrlString) else { return }
URLSession.shared.dataTask(with: url) { (data, response, err) in
guard let data = data else { return }
do {
self.arrayOfLaunchData = try JSONDecoder().decode([launchData].self, from: data)
print(launchDataDecoded)
DispatchQueue.main.async {
self.launchTableView.reloadData()
}
} catch {
print("Error Serialization json:", error )
}
}.resume()
print("getJsonData ran")
}
because dataTask works asynchronously.
Note:
Please conform to the naming convention that struct and class names start with a capital letter (LaunchData, RocketInfo) and all names are supposed to be camelCased rather than snake_cased.

Answer 2

Remove self.launchTableView.reloadData() from viewDidLoad()
and put on getting successfully data
do {
let launchDataDecoded = try JSONDecoder().decode([launchData].self, from: data)
print(launchDataDecoded)
self.launchTableView.reloadData()
} catch let jsonErr {
print("Error Serialization json:", jsonErr )
}
}.resume()
getJsonData() is follow asynchronous. hope this help!