Table Cell Not Swiping - ios

Question

I'm developing a todo list app that links up with a Realm database, however when I'm trying to use the 'editingStyle' method which allows users to swipe on the cell to delete the data from the UI & the Realm database the cell doesn't swipe, the app has 2 screens, this method works fine on one the first one but it does not work on the other screen, the cell works fine it just won't swipe.
My code:
import UIKit
import RealmSwift
class CategoryViewController: UITableViewController {
var categories: Results<Category>?
let realm = try! Realm()
override func viewDidLoad() {
super.viewDidLoad()
loadCategories()
tableView.rowHeight = 60.0
}
//MARK: - Creating the table view cell
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return categories?.count ?? 0
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "CategoryCell", for: indexPath)
cell.textLabel?.text = categories?[indexPath.row].name ?? "No Categories Added Yet"
return cell
}
//MARK: - This will remove a category from the UI & the Realm database, this is a built in swift method
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
if let deleteAction = categories?[indexPath.row] {
do {
try realm.write({
realm.delete(deleteAction)
})
} catch {
print("Error deleting the cell \(error)")
}
}
}
tableView.deleteRows(at: [indexPath], with: .fade)
}
//MARK: - TableView Delegate Methods
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
performSegue(withIdentifier: "goToItems", sender: self)
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let destinationVC = segue.destination as! TodoListViewController
if let indexPath = tableView.indexPathForSelectedRow {
destinationVC.selectedCategory = categories?[indexPath.row]
}
}
//MARK: - Add New Categories
#IBAction func addButtonPressed(_ sender: UIBarButtonItem) {
var textField = UITextField()
let alert = UIAlertController(title: "Add New Category", message: "", preferredStyle: .alert)
let action = UIAlertAction(title: "Add", style: .default) { (action) in
// What happens when user clicks add button
let newCategory = Category()
newCategory.name = textField.text!
self.saveCategories(category: newCategory)
}
alert.addAction(action)
alert.addTextField { (field) in
textField = field
textField.placeholder = "Add a new category"
}
present(alert, animated: true, completion: nil)
}
//MARK: - Data Manipulation Methods
func saveCategories(category: Category) {
do {
try realm.write({
realm.add(category)
})
} catch {
print("Error saving category \(error)")
}
tableView.reloadData()
}
func loadCategories() {
categories = realm.objects(Category.self)
tableView.reloadData()
}
}

Answer 1

Add this:
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}

Answer 2

Your code seems correct. I think there's something wrong with realm.delete(_:) method which possibly throws an error which executes the catch block instead of deleting the row. Try to see if there is something wrong within the try block with a few print statements. And if all fails, try making the following changes
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
if let deleteAction = categories?[indexPath.row] {
do {
try realm.write({
realm.delete(deleteAction)
})
// New snippet
tableView.deleteRows(at: indexPath, with: .fade)
self.tableView.reloadData()
} catch {
print("Error deleting the cell \(error)")
}
}
}
}