Automatic re-ordering of Core Data in Swift - xcode

Question

I am trying to reorder a my Core Data list when moving cells in "Edit Mode". There seems to be helpful discussion in this area for Obj-c (see links below), but I can't find anything in Swift.
Has anyone come across any related documentation for Swift? Or would anyone be willing to translate the obj-c code to Swift? Thanks!
Obj-c links:
How can I maintain display order in UITableView using Core Data?
How to implement re-ordering of CoreData records?

Answer 1

Here is a nice way I do it. It also checks if the destination may not contain any data and you can also move accross sections.
isMoving will inhibit the delegate from firing off. You also need a sortorder attribute at your entity.
private func indexIsOutOfRange(indexPath:NSIndexPath) -> Bool {
if indexPath.section > self.fetchedResultsController.sections!.count - 1 {
return true
}
if indexPath.row > self.fetchedResultsController.sections![indexPath.section].objects!.count - 1 {
return true
}
return false
}
override func tableView(tableView: UITableView, moveRowAtIndexPath sourceIndexPath: NSIndexPath, toIndexPath destinationIndexPath: NSIndexPath)
{
if indexIsOutOfRange(destinationIndexPath) {
return
}
isMovingItem = true
if sourceIndexPath.section == destinationIndexPath.section {
if var todos = self.fetchedResultsController.sections![sourceIndexPath.section].objects {
let todo = todos[sourceIndexPath.row] as! FoodEntry
todos.removeAtIndex(sourceIndexPath.row)
todos.insert(todo, atIndex: destinationIndexPath.row)
var idx = 1
for todo in todos as! [FoodEntry] {
todo.sortOrder = NSNumber(integer: idx++)
}
try!managedObjectContext.save()
}
} else {
if var allObjectInSourceSection = fetchedResultsController.sections![sourceIndexPath.section].objects {
let object = allObjectInSourceSection[sourceIndexPath.row] as! FoodEntry
allObjectInSourceSection.removeAtIndex(sourceIndexPath.row)
for (index,object) in (allObjectInSourceSection as! [FoodEntry]).enumerate() {
object.sortOrder = NSNumber(integer: index)
}
if var allObjectInDestinationSection = fetchedResultsController.sections![destinationIndexPath.section].objects {
allObjectInDestinationSection.insert(object, atIndex: destinationIndexPath.row)
for (index,object) in (allObjectInDestinationSection as! [FoodEntry]).enumerate() {
object.sortOrder = NSNumber(integer: index)
object.section = NSNumber(integer: destinationIndexPath.section)
}
}
}
}
dispatch_async(dispatch_get_main_queue(), { () -> Void in
tableView.reloadRowsAtIndexPaths(tableView.indexPathsForVisibleRows!, withRowAnimation: .Fade)
})
isMovingItem = false
try!managedObjectContext.save()
fetch()
}