Swift UITableView does not show up the content - ios

Question

I have a side menu and for each selection I want to load a new ViewController (basically each page has a separate ViewController).
This is the relevant code where I load a new ViewController:
viewController = storyboard!.instantiateViewController(withIdentifier: "commissionsViewController")
var viewInAction = UIView()
viewInAction = viewController.view
let gestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.tapOnView))
viewInAction.addGestureRecognizer(gestureRecognizer)
viewInAction.layer.backgroundColor = UIColor(red: 0.0, green: 0.0, blue: 0.0, alpha: 0.0).cgColor
viewInAction.translatesAutoresizingMaskIntoConstraints = false
if let subview = containerView.viewWithTag(100) {
subview.removeFromSuperview()
}
containerView.insertSubview(viewInAction, belowSubview: menuView)
setConstrainsOnView(viewObject: viewInAction)
This is the code for the ViewController that is loaded:
import UIKit
class CommissionsViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
var tableView = UITableView()
var tableData = ["Beach", "Clubs", "Chill", "Dance"]
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
tableView = UITableView(frame: self.view.bounds, style: UITableViewStyle.plain)
tableView.dataSource = self
tableView.delegate = self
tableView.backgroundColor = UIColor.blue
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "my")
tableView.contentInset.top = 20
let contentSize = self.tableView.contentSize
let footer = UIView(frame: CGRect(x: self.tableView.frame.origin.x,
y: self.tableView.frame.origin.y + contentSize.height,
width: self.tableView.frame.size.width,
height: self.tableView.frame.height - self.tableView.contentSize.height))
self.tableView.tableFooterView = footer
view.addSubview(tableView)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "my", for: indexPath)
cell.textLabel?.text = "This is row \(tableData[indexPath.row])"
return cell
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return tableData.count
}
The problem: As you can see the CommissionsViewController contains a tableView that is added programatically. That tableView does not show up any cell! Basically the method cellForRowAt is never called! And I don't understand why!
I can see a blue view, which is the tableView's background, so the tableView is in place, but it doesn't load the cells!
The method numberOfRowsInSection is called.
I tried to debug it using the debugger but no result. I simply don't understand the flow.
Thank you respectfully.

Answer 1

When you add another viewController's view to your view hierarchy, you must tell both viewControllers (see this answer for further information).
Add the addChildViewController and didMoveToParentViewController calls like this:
viewController = storyboard!.instantiateViewController(withIdentifier: "commissionsViewController")
self.addChildViewController(viewController)
var viewInAction = viewController.view
let gestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.tapOnView))
viewInAction.addGestureRecognizer(gestureRecognizer)
viewInAction.layer.backgroundColor = UIColor(red: 0.0, green: 0.0, blue: 0.0, alpha: 0.0).cgColor
viewInAction.translatesAutoresizingMaskIntoConstraints = false
if let subview = containerView.viewWithTag(100) {
subview.removeFromSuperview()
}
containerView.insertSubview(viewInAction, belowSubview: menuView)
setConstrainsOnView(viewObject: viewInAction)
viewController.didMoveToParentViewController(self)

Answer 2

After you set the dataSource and he delegate to self, you never make the tableView load any data. That means you need to call tableView.reloadData() at the end of viewDidLoad()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
tableView = UITableView(frame: self.view.bounds, style: UITableViewStyle.plain)
tableView.dataSource = self
tableView.delegate = self
tableView.backgroundColor = UIColor.blue
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "my")
tableView.contentInset.top = 20
let contentSize = self.tableView.contentSize
let footer = UIView(frame: CGRect(x: self.tableView.frame.origin.x,
y: self.tableView.frame.origin.y + contentSize.height,
width: self.tableView.frame.size.width,
height: self.tableView.frame.height - self.tableView.contentSize.height))
self.tableView.tableFooterView = footer
view.addSubview(tableView)
tableView.reloadData()
}

Answer 3

In viewDidLoad method view is loaded but has incorrect size.
Try to change initialization of UITableView in next way
let screenBounds = UIScreen.main.bounds
let rect = CGRect(x: 0, y: 0, width: screenBounds.width, height: screenBounds.height)
tableView = UITableView(frame: rect, style: UITableViewStyle.plain)

Answer 4

Go to ComissionsViewController, viewDidLoad() method and add tableView.reloadData() right after view.addSubview(tableView) — it makes all your troubles disappear.
UPD: I have just made a test project where it works. I have copied the code you posted and only commented a couple of unrelated lines. The only significant difference I made is adding the line of code I mentioned above. You can download and run it to see it works :)
https://drive.google.com/file/d/0B55tO8S_7Ag7VnppMk1fWlg5dWM/view