UiTableView number of generated cells - ios

Question

I have two viewControllers. The first with a stepper:
var steppers : UIStepper?
#IBOutlet weak var hourLabel: UILabel!
#IBOutlet weak var stepper: UIStepper!
#IBAction func stepper(_ sender: UIStepper) {
hourLabel.text = String(sender.value)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let np = segue.destination as? CourseClass2 {
np.numberPlaces = Int(stepper.value)
}
}
and the second with a tableView:
private let resueIdentifier = "MyTableViewCell"
extension UIViewController {
func present(viewController : UIViewController, completion : (() -> ())? = nil ){
if let presented = self.presentedViewController {
presented.dismiss(animated: true, completion: {
self.present(viewController, animated: true, completion: completion)
})
} else {
self.present(viewController, animated: true, completion: completion)
}
}
}
class CourseClass2: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var tableView: UITableView!
var locationManager:CLLocationManager?
let minimumSpacing : CGFloat = 15 //CGFloat(MAXFLOAT)
let cellWidth: CGFloat = 250
let radius = 5000 // 5km
var category : QCategoryy?
var currentLocation : CLLocationCoordinate2D?
var places: [QPlace] = []
var isLoading = false
var response : QNearbyPlacesResponse?
var rows = 0
var numberPlaces = 0
override func viewDidLoad() {
super.viewDidLoad()
self.title = category?.name
tableView.dataSource = self
tableView.delegate = self
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
determineMyCurrentLocation()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
rows = 0
/* insertRowsMode3()
tableView.reloadData() */
category?.markView()
}
#IBAction func refreshTapped(_ sender: Any) {
rows = 0
/* insertRowsMode3() */
tableView.reloadData()
}
func canLoadMore() -> Bool {
if isLoading {
return false
}
if let response = self.response {
if (!response.canLoadMore()) {
return false
}
}
return true
}
func loadPlaces(_ force:Bool) {
if !force {
if !canLoadMore() {
return
}
}
print("load more")
isLoading = true
NearbyPlaces.getNearbyPlaces(by: category?.name ?? "food", coordinates: currentLocation!, radius: radius, token: self.response?.nextPageToken, completion: didReceiveResponse)
}
func didReceiveResponse(response:QNearbyPlacesResponse?, error : Error?) -> Void {
if let error = error {
let alertController = UIAlertController(title: "Error", message: error.localizedDescription, preferredStyle: .alert)
let actionDismiss = UIAlertAction(title: "Dismiss", style: .cancel, handler: nil)
let actionRetry = UIAlertAction(title: "Retry", style: .default, handler: { (action) in
DispatchQueue.main.async {
self.loadPlaces(true)
}
})
alertController.addAction(actionRetry)
alertController.addAction(actionDismiss)
DispatchQueue.main.async {
self.present(viewController: alertController)
}
}
if let response = response {
self.response = response
if response.status == "OK" {
if let placesDownloaded = response.places {
places.append(contentsOf: placesDownloaded)
}
self.tableView?.reloadData()
} else {
let alert = UIAlertController.init(title: "Error", message: response.status, preferredStyle: .alert)
alert.addAction(UIAlertAction.init(title: "Cancel", style: .cancel, handler: nil))
alert.addAction(UIAlertAction.init(title: "Retry", style: .default, handler: { (action) in
DispatchQueue.main.async {
self.loadPlaces(true)
}
}))
self.present(viewController: alert)
}
isLoading = false
}
else {
print("response is nil")
}
}
func numberOfSections(in tableView: UITableView) -> Int {
print("numberOfsection Call")
return 1
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print("numberOfRows Call")
return places.count /* rows */
}
public func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: resueIdentifier, for: indexPath) as! MyTableViewCell
let place = places[indexPath.row]
cell.update(place: place)
if indexPath.row == places.count - 1 {
loadPlaces(false)
}
print("CellForRow Call")
return (cell)
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
UIView.animate(withDuration: 0.2, animations: {
let cell = tableView.dequeueReusableCell(withIdentifier: "MyTableViewCell", for: indexPath) as! MyTableViewCell
})
performSegue(withIdentifier: "goToLast" , sender: indexPath.row)
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 100
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == UITableViewCellEditingStyle.delete {
places.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .fade)
}
}
func didReceiveUserLocation(_ userLocation:CLLocation) {
currentLocation = userLocation.coordinate
loadPlaces(true)
}
I added only the code useful for the question. As you can see I'm trying to pass from the first VC to the second this value:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let np = segue.destination as? CourseClass2 {
np.numberPlaces = Int(stepper.value)
}
}
Because I would like to add a limit to the number of cells that spawn when loading the tableview in the second viewController (and I want this limit to be chosen by the user with the stepper in the previous controller), how do I have to modify the tableView to make sure that the number of cells generated is equal to the value of var numberPlaces?

Answer 1

I would suggest that you limit the number of cells inside UITableView delegate method number of cells
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
print("numberOfRows Call")
if places.count < self.numberPlaces {
return places.count /* rows */
}
return self.numberPlaces
}
In this way, you will get right number of cells, but if there would be too many places only self.numberPlaces will be displayed.
Maybe, you would need to figure out some sorting, so that correct places would be displayed. (By proximity,...)