CODEWITHSUNDEEP
iosswiftuitableviewcore-data
Michael Rowe
Michael Rowe

Reputation: 956

tableview commit editingStyle is removing the wrong entry

The following code is deleting the wrong entry. I have an array that shows a list of events. in the debugger indexPath.row shows 1 (which is the entry I selected to delete. However when the view refreshes it has deleted the entry 4.

func tableView(_ tableView: UITableView,
                        commit editingStyle: UITableViewCellEditingStyle,
                        forRowAt indexPath: IndexPath) {
    print(type(of: selectedRecipient))

    var eventsOnArray = selectedRecipient?.events?.allObjects 

    guard let event = eventsOnArray?[indexPath.row] as? Event, editingStyle == .delete else {
                return
    }
        managedContext.delete(event)
        do {
            try managedContext.save()
            print("Deleted")
            eventsOnArray?.remove(at: indexPath.row)
            getEvents()
            self.eventList.reloadData()
        } catch let error as NSError {
            print("Saving error: \(error), description: \(error.userInfo)")
        }

}

Upvotes: 0

Views: 93

Answers (2)

Tom E
Tom E

Reputation: 1607

Adding to @Joakim Danielson’s answer, you would add an extension for your entity to provide for an array instead of a set, like this:

extension Recipient {
    var eventsArray: [Event] {
        get {
            if let eventSet = events as? Set<Event> {
                return eventSet.sorted { (item0, item1) -> Bool in
                    return item0.title < item1.title
                }
            }
            return []
        }
    }
}

This assumes there is a title attribute in your Event entity so the array returns all events sorted by title. Modify the sorted closure according to your needs.

Upvotes: 0

Joakim Danielson
Joakim Danielson

Reputation: 52013

My guess here is that the order of your data source is not the same as the array you use in the code we see.

I base this on the fact that you call events?.allObjects which suggests that events is a NSSet which is unordered and calling allObjects on it gives you an array with an undefined order. You need to have an array instead of a set so you can guarantee the same sort order of your objects through different parts of your code.

Upvotes: 1

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