How to implement edit/delete behaviour on an embedded tableView? - swift

Question

So I have an embedded tableview and I want to implement edit/delete behaviour:
In my HomePageViewController I have:
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.leftBarButtonItem = editButtonItem
}
However, all that happens is when I click on the edit button, it says done, and the embedded tableview does nothing at all. When I put the above code in the tableview nothing happens.
How do I get the navigation controller/parent view controller to recognise the embedded table view?

Answer 1

It looks like you're using an embed segue to embed a UITableViewController. In your parent view controller, you can do 1 of 2 things easily to achieve you goal.
Method 1: Use the child view controller's edit button
override func viewDidLoad() {
super.viewDidLoad()
// Find and (optionally assign it to a variable for later convenience) the embedded controller, IBOutlets aren't available for VCs embedded within a storyboard
let childControllers = childViewControllers.filter { return $0 is EventTableViewController }
let embeddedController = childControllers[0] as! EventTableViewController
navigationItem.leftBarButtonItem = embeddedController.editButtonItem
}
Method 2: Forward edit events to child view controllers
override func viewDidLoad() {
super.viewDidLoad()
navigationItem.leftBarButtonItem = editButtonItem
}
override func setEditing(_ editing: Bool, animated: Bool) {
super.setEditing(editing, animated: animated)
// Forward editing state to children
childViewControllers.forEach { $0.setEditing(editing, animated: animated) }
}
Note: editButtonItem was exposed in iOS 10 (but was implemented much earlier). For deployment targets less than iOS 10, you can use a custom edit button combined with method 2.

Answer 2

In this situation, you can't use the automatic behavior of the edit button. It's up to you to implement it yourself. You need to toggle both the isEditing of the table view and the appearance of the button. Here's an example from one of my own apps:
func doEdit(_ sender: Any?) {
var which : UIBarButtonSystemItem
if !self.tableView.isEditing {
self.tableView.setEditing(true, animated:true)
which = .done
} else {
self.tableView.setEditing(false, animated:true)
which = .edit
}
let b = UIBarButtonItem(barButtonSystemItem: which,
target: self, action: #selector(doEdit))
self.navigationItem.rightBarButtonItem = b
}