UITableVIew swipe trailingSwipeActionsConfigurationForRowAt not working - ios

Question

New iOS 11 UITableView Swipe action not getting called. The delegate and datasource are working fine for the table.
I am not able to swipe and see the menu items.
Below is my code for the same.
func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let contextItem = UIContextualAction(style: .normal, title: "Leading & .normal") { (contextualAction, view, boolValue) in
print("Leading Action style .normal")
}
let swipeActions = UISwipeActionsConfiguration(actions: [contextItem])
return swipeActions
}
func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let contextItem = UIContextualAction(style: .destructive, title: "Trailing & .destructive") { (contextualAction, view, boolValue) in
print("Trailing Action style .destructive")
}
let swipeActions = UISwipeActionsConfiguration(actions: [contextItem])
return swipeActions
}
I tried to call below and its working fine.
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
}
}
Any hint in right direction is highly appreciated.

Answer 1

You need to pass true to UIContextualAction in the closure boolValue(true). Otherwise the handler won't allow the action.
func tableView(_ tableView: UITableView, leadingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? {
let contextItem = UIContextualAction(style: .normal, title: "Leading & .normal") { (contextualAction, view, boolValue) in
boolValue(true) // pass true if you want the handler to allow the action
print("Leading Action style .normal")
}
let swipeActions = UISwipeActionsConfiguration(actions: [contextItem])
return swipeActions
}

Answer 2

For those who uses UITableViewDiffableDataSource you need to subclass it and override its canEditRowAt method.
public override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
true
}

Answer 3

Code looks good, but you are missing probably missing the following the "UITableViewDelegate" in the Class declaration and also the "TableView.delegate = self" in the viewdidload() section. So it should look like:
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = self
tableView.delegate = self
}
}