Swift- alert action handler assistance?

Question

I'm using a tutorial to add an email and iMessage "share" action from a custom table view cell. But I am confused. The tutorial stops as "print ln" when invoking the action. But doesn't explain the handler. Can anyone help?

I added the (ACTION :UIAlertAction!)in}) as a placeholder, as a guess, but not sure where to go with the rest.

Thank you.

 override func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction] {

        let shareAction = UITableViewRowAction(style: UITableViewRowActionStyle.Default, title: "Share", handler: { (action:UITableViewRowAction!, indexPath:NSIndexPath!) -> Void in

            let shareMenu = UIAlertController(title: nil, message: "Send mail", preferredStyle: .ActionSheet)
            let emailAction = UIAlertAction(title: "Email", style:UIAlertActionStyle.Default, handler:  { (ACTION :UIAlertAction!)in})



            let imessageAction = UIAlertAction(title: "iMessage", style: UIAlertActionStyle.Default, handler:  {
                (ACTION :UIAlertAction!)in})

            let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel, handler: nil)

            shareMenu.addAction(emailAction)
            shareMenu.addAction(imessageAction)
            shareMenu.addAction(cancelAction)



            self.presentViewController(shareMenu, animated:  true, completion: nil)
            }

                )
        shareAction.backgroundColor = UIColor(red: 109.0/255.0, green: 188.0/255.0, blue: 219.0/255.0, alpha: 1.0)


        return [shareAction]

Answer 1

First, you should create UIAlertController, then create UIAlertActions and setup handlers. Then create UITableViewRowAction. You got it somewhat mixed up. Here is the code with documentation. It's pretty much self-explanatory.

override func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]? {

        // Construct alert controller first
        let shareController = UIAlertController(title: nil, message: "Send mail", preferredStyle: .ActionSheet)

        // Create email, iMessage and cancel actions
        let emailAlertAction = UIAlertAction(title: "Email", style: .Default) {
            action in
            let emailController = MFMailComposeViewController()
            if MFMailComposeViewController.canSendMail() {
                emailController.setSubject("This is subject")
                // Additional configuration
                self.showViewController(emailController, sender: self)
            }
        }

        let iMessageAlertAction = UIAlertAction(title: "iMessage", style: .Default) {
            action in
            print("iMessage action is selected")
        }

        let cancelAlertAction = UIAlertAction(title: "Cancel", style: .Cancel) {
            action in
            // do nothing
        }

        // Add actions to alert controller
        shareController.addAction(emailAlertAction)
        shareController.addAction(iMessageAlertAction)
        shareController.addAction(cancelAlertAction)

        // Create shared action
        let shareAction = UITableViewRowAction(style: .Normal, title: "Share") {
            action, indexPath in
            // What happens when someone taps on Share
            print("selected share at cell index \(indexPath.row)")
            self.showViewController(shareController, sender: self)
        }
        shareAction.backgroundColor = UIColor(red: 109.0/255.0, green: 188.0/255.0, blue: 219.0/255.0, alpha: 1.0)

        return [shareAction]
    }

Answer 2

I'm not sure what you want? If you want to handle an action? First of all you'll need to create an UIAlertController. And add an UIAlertAction to it.

let alertController = UIAlertController(title: "Title", message: "Message", preferredStyle: .Alert) alertController.addAction(UIAlertAction(title: "Ok", style: .Default, handler: self.handler)) self.presentViewController(alertController, animated: true, completion: nil)

And your handler function:

func handler(action:UIAlertAction) { // Do something }