I have a CoreData app with a fairly long list of data fields. When a user edits the fields but attempts to exit the DetailViewController without saving the edits, I put up an alert asking if they really want to discard the changes. This works fine, but if the user taps the home key, the edits are lost. I've tried to present an alert before the app enters the background but have been unable to delay entry into background to allow for user input. Is it possible to delay app entry into the background while waiting for user input?
Here's what I tried:
func applicationWillResignActive(_ notification : Notification) {
//this does not work - alert is too late
cancelUnsavedEdits()
//try above
}//applicationWillResignActive
The canelUnsavedEdits method is fairly straight forward:
func cancelUnsavedEdits() {
if hasChanged {
let ac = UIAlertController(title: nil, message: nil, preferredStyle: .alert)
ac.addAction(UIAlertAction(title: "Delete Edits", style: .default, handler: { (action : UIAlertAction!) -> Void in
self.codeDismissTheKeyboard()
self.performSegue(withIdentifier: "unwindToMasterViewController", sender: self)
let editRecordButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.edit, target: self, action: #selector(DetailViewController.editThisRecord))
self.navigationItem.rightBarButtonItem = editRecordButton
self.navigationItem.leftBarButtonItem = nil
self.navigationItem.hidesBackButton = false
//need to remove the edits - refresh the original page
self.configureView()
}))//addAction block
ac.addAction(UIAlertAction(title: "Save Edits", style: .default, handler: { (action : UIAlertAction!) -> Void in
self.codeDismissTheKeyboard()
self.saveTheEditedRecord()
self.performSegue(withIdentifier: "unwindToMasterViewController", sender: self)
}))//addAction block
//for -ipad add code in handler to reopen the fields for editing if the cancel of the cancel is chosed
ac.addAction(UIAlertAction(title: "Cancel", style: .default, handler: { (whatever) in
//print("makeEntryFieldsEnabledYES for ipad")
self.makeEntryFieldsEnabledYES()
}))
//above for ipad
self.present(ac, animated: true, completion: nil)
} else {
self.codeDismissTheKeyboard()
//add this for ipad
self.navigationItem.rightBarButtonItem = nil
//add above for ipad
self.performSegue(withIdentifier: "unwindToMasterViewController", sender: self)
}//if hasChanged
//this for ipad
navigationItem.leftBarButtonItem = nil
//above for iPad
}//cancelUnsavedEdits
Any guidance on a strategy to accomplish this idea would be appreciated. iOS 10, Xcode 8.1
