How to Save the Checkmark Accessory in A Cell - ios

Question

Trying to develop a checklist app and have been stuck for a while trying to save the state of a checkmark. When I go off the tableView and back on all of the saved checkmarks are erased. I have imported UKIT then defined the class.
Here is my code:
var PreDefinedTasks = ["1", "2", "3", "4"]
// MARK: - Table view data source
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
if let cell = tableView.cellForRow(at: indexPath as IndexPath) {
if cell.accessoryType == .checkmark{
cell.accessoryType = .none
}
else{
cell.accessoryType = .checkmark
}
}
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return PreDefinedTasks.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "List1", for: indexPath)
cell.textLabel?.text = PreDefinedTasks[indexPath.row]
return cell
}
I have looked into NSCoder as a solution but cant seem to get it to work properly. Any help is appreciated!

Answer 1

Here is how I would go about it, if you follow the whole solution, it will save even when the app closes.
Make an array off type Bool like this: var checkmarks = [Int : Bool]()
Then, in cellForRow function, add this:
if checkmarks[indexPath.row] != nil {
cell.accessoryType = checkmarks[indexPath.row] ? .checkmark : .none
} else {
checkmarks[indexPath.row] = false
cell.accessoryType = .none
}
And in the didSelectRow function, add this:
if let cell = tableView.cellForRow(at: indexPath as IndexPath) {
if cell.accessoryType == .checkmark{
cell.accessoryType = .none
checkmarks[indexPath.row] = false
}
else{
cell.accessoryType = .checkmark
checkmarks[indexPath.row] = true
}
}
If you want it to save when the app closes, you have to save the checkmarks array in UserDefaults by doing this:
In didSelectRow function, at the bottom after everything add this:
UserDefaults.standard.set(NSKeyedArchiver.archivedData(withRootObject: checkmarks), forKey: "checkmarks")
UserDefaults.standard.synchronize()
Then also, in viewDidLoad, add this:
if let checks = UserDefaults.standard.value(forKey: "checkmarks") as? NSData {
checkmarks = NSKeyedUnarchiver.unarchiveObject(with: checks as Data) as! [Int : Bool]
}
Let me know if this answer helped and if you have any questions.
EDIT:
So what I completely forgot about is that [Int : Bool] is not an NSDictionary, it is just a Dictionary. UserDefaults can't store Dictionary objects, only NSDictionary which is why you have to change it to NSData so it is able to save the [Int : Bool]. Hope it works this time :)

Answer 2

You can save the indexpath in your array based on checkmark selected on your tableView rows.

Answer 3

As per you implementation, the UITableViewCell is getting reused with identifier as "List1". So if you want to re-use the cell then you have to keep updating the correct accessoryType by storing the state against the predefines tasks.

Answer 4

Since cells get unloaded and later reused, you'll need to store the state of the checkmark elsewhere. In this example in an array called preDefinedTaskCheckmarkState. When loading the cells you'll also need to set the checkmark state.
var PreDefinedTasks = ["1", "2", "3", "4"]
var preDefinedTaskCheckmarkState = [Bool](repeating: false, count: 4)
// MARK: - Table view data source
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
if let cell = tableView.cellForRow(at: indexPath as IndexPath) {
preDefinedTaskCheckmarkState[indexPath.row] = !(cell.accessoryType == .checkmark)
cell.accessoryType = preDefinedTaskCheckmarkState[indexPath.row] ? .checkmark : .none
}
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return PreDefinedTasks.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "List1", for: indexPath)
cell.textLabel?.text = PreDefinedTasks[indexPath.row]
cell.accessoryType = preDefinedTaskCheckmarkState[indexPath.row] ? .checkmark : .none
return cell
}