How to do an undo function within a tableviewcell? - swift

Question

I am having troubles getting my undo button working. I'm trying to get it to where if you press the delete button on a tableview cell, the undo can re-enter the cell.
My undo:
#IBAction func undoBtnWasPressed(_ sender: Any) {
undoItem()
undoView.isHidden = true
}
func undoItem() {
undoManager?.registerUndo(withTarget: GoalCell.self, selector: #selector(removeGoal(atIndexPath:)), object: nil)
undoManager?.undo()
}
My remove:
#objc func removeGoal(atIndexPath indexPath: IndexPath) {
guard let managedContext = appDelegate?.persistentContainer.viewContext else { return }
managedContext.delete(goals[indexPath.row])
undoView.isHidden = false
do {
try managedContext.save()
print("Successfully removed goal.")
} catch {
debugPrint("Could not save: \(error.localizedDescription)")
}
}

Answer 1

You can just save the data from the datasource of the deleted cell in a property or an array and if the undo button is pressed, you re-add the data into the datasource and reload the row or the full data of the tableview.
EDIT
So for instance, in your example you had the delete function delete data from core data based on goals[indexPath.row]
Before deleting, save the content from goals[indexPath.row] into a separate array.
When undo is tapped, just grab the value from the separate array and add it back to goals and add it back into core data.
Then just do a tableview.reloadData()
EDIT 2:
let dataSource: [CustomObject] = [Object1, Object2, Object3]
var undoSource: [CustomObject] = []
func removeRow(indexPath) {
let object = dataSource[indexPath.row]
undoSource.append(object)
dataSource.remove(object)
}
func undo() {
for object in undoSource {
dataSource.append(object)
}
tableView.reloadData()
}