Separating ViewController and UITableViewDataSource - ios

Question

I'm trying to clean up my crowded ViewController by moving the UITableViewDataSource (and Delegate) to a seperate class.
While the DataSource was inside the ViewController (see just below), it worked fine
class ViewController: UIViewController, UITableViewDataSource{
//MARK: Properties
#IBOutlet weak var myTableView: UITableView!
let cellIdentifier = "myTableViewCell"
let myArray = ["Label one", "Label two", "Label three"]
override func viewDidLoad()
{
super.viewDidLoad()
myTableView.dataSource = self
}
override func didReceiveMemoryWarning()
{super.didReceiveMemoryWarning()}
//MARK: TableViewDataSource
func numberOfSectionsInTableView(tableView: UITableView) -> Int
{return 1}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{return myArray.count}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! myTableViewCell
cell.myLabel.text = myArray[indexPath.row]
return cell
}
}
With The myTableViewCell class
class myTableViewCell: UITableViewCell{
#IBOutlet weak var myLabel: UILabel!
override func awakeFromNib()
{super.awakeFromNib()}
override func setSelected(selected: Bool, animated: Bool)
{super.setSelected(selected, animated: animated)}
}
And this works fine and populates a basic table with the labels filled from the strings in myArray.
However when I move the DataSource to it's own class, as follows, it doesn't work
ViewController
class ViewController: UIViewController
{
//MARK: Properties
#IBOutlet weak var myTableView: UITableView!
override func viewDidLoad()
{
super.viewDidLoad()
myTableView.dataSource = myDataSource()
}
override func didReceiveMemoryWarning()
{super.didReceiveMemoryWarning()}
}
and here's the myDataSource class
class myDataSource: NSObject, UITableViewDataSource
{
let cellIdentifier = "myTableViewCell"
let myArray = ["Label one", "Label two", "Label three"]
//MARK: TableViewDataSource
func numberOfSectionsInTableView(tableView: UITableView) -> Int
{return 1}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{return myArray.count}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! myTableViewCell
cell.myLabel.text = myArray[indexPath.row]
return cell
}
}
(The myTableViewCell remains the same)
This setup just outputs an empty table, even though all I did was copy-paste the code from the ViewController to myDataSource. What am I missing? (aside form the delegate. I'll deal with that later, first I need to find what's the problem with the data source).
I'm a bit of a rookie to swift, so I'm having a really rough time understanding where I'm going wrong here. Any help at all would be greatly appreciated. If you could just remember in your answer that I'm just starting out, so try not to throw too many complicated concepts at me without explaining. Thanks

Answer 1

Probably the code in your data source never gets called because your data source doesn't get retained by the table here myTableView.dataSource = myDataSource() so basically gets released right away. To solve this, keep the data source as a property.

Answer 2

Declare the separate class as an extension of the ViewController class
extension ViewController: UITableViewDataSource
{
let cellIdentifier = "myTableViewCell"
let myArray = ["Label one", "Label two", "Label three"]
//MARK: TableViewDataSource
func numberOfSectionsInTableView(tableView: UITableView) -> Int
{return 1}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{return myArray.count}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
let cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier, forIndexPath: indexPath) as! myTableViewCell
cell.myLabel.text = myArray[indexPath.row]
return cell
}
}
I'm using also always delegate methods in an extension declaration but in the same file as the main class