swift protocol with uitableviewdatasource [duplicate] - ios

Question

This question already has an answer here:
How can you provide default implementations for UIPageViewControllerDataSource?
(1 answer)
Closed 6 years ago.
I want to reuse the code below
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 3
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 5
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
return UITableViewCell()
}
I define a protocol :
protocol ConfigDetail: class, UITableViewDataSource{}
extension ConfigDetail{
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 3
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 5
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
return UITableViewCell()
}
}
but when i use the protocol with a UIViewController, it always tells me i did not conform to protocol UITableViewDataSource, or i have to add #objc before my protocol. But i have struct variables defined in my protocol, #objc may not help. Any solutions?

Answer 1

If you want to implement these data source methods and reuse them, just define a data source class that implements them. And then rather than implementing the delegate methods in the view controller, instantiate a data source object, keep a strong reference to it, and specify it as the data source for the table view.
For example:
class DataSource: NSObject, UITableViewDataSource {
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 3
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 5
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)
// configure cell here
return cell
}
}
class ViewController: UITableViewController {
let dataSource = DataSource()
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = dataSource
}
}