Swift - No data displayed in TableView after Retrieving it from UserDefaults - swift

Question

I am trying to get the data I have saved and then load it into the TableView. Currently, if I am saving the object for the first time, the data gets encoded, saved, decoded, read and displayed correctly. However, if the key already exists and I am adding to the existing data, nothing gets displayed in the TableView.
This is currently how I am saving it in the first view controller:
let userEntry = UserEntries(date: String(todayDate), questions: [UserEntries.Question(question: q1Text, answer: q1Answer), UserEntries.Question(question: q2Text, answer: q2Answer)])
var allEntries : [UserEntries] = []
if doesKeyExist(key: "allEntries") == true {
let jsonDecoder = JSONDecoder()
if let data = UserDefaults.standard.data(forKey: "allEntries"),
let userEntries = try? jsonDecoder.decode(UserEntries.self, from: data) {
allEntries = [userEntries]
}
allEntries.insert(userEntry, at: 0)
let jsonEncoder = JSONEncoder()
if let value = try? jsonEncoder.encode(allEntries) {
UserDefaults.standard.set(value, forKey: "allEntries")
UserDefaults.standard.synchronize()
}
} else {
let jsonEncoder = JSONEncoder()
if let value = try? jsonEncoder.encode(userEntry) {
UserDefaults.standard.set(value, forKey: "allEntries")
UserDefaults.standard.synchronize()
}
}
let newViewController = storyboard?.instantiateViewController(withIdentifier: "tabViewController") as! UITabBarController
present(newViewController, animated: true, completion: nil)
}
This is how I'm displaying it in the TableView
var TableData : [UserEntries] = []
override func viewDidLoad() {
super.viewDidLoad()
let jsonDecoder = JSONDecoder()
if let data = UserDefaults.standard.data(forKey: "allEntries"),
let userEntries = try? jsonDecoder.decode(UserEntries.self, from: data) {
print(userEntries.date)
TableData = [userEntries]
}
// Uncomment the following line to preserve selection between presentations
// self.clearsSelectionOnViewWillAppear = false
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return TableData.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "entryCell", for: indexPath)
cell.textLabel?.text = TableData[indexPath.row].date
cell.detailTextLabel?.text = TableData[indexPath.row].questions[0].answer
return cell
}
I have a feeling that this is a logic error, in getting/displaying the data in the TableView, but am unsure of what exactly it is/how to fix it. Thank you for your help!

Answer 1

I don't know what your doesKeyExists function does but you can improve your data manipulation by this way:
let userEntry = UserEntries(date: String(todayDate), questions: [UserEntries.Question(question: q1Text, answer: q1Answer), UserEntries.Question(question: q2Text, answer: q2Answer)])
var allEntries : [UserEntries] = []
let jsonDecoder = JSONDecoder()
if let data = UserDefaults.standard.data(forKey: "allEntries"),
let userEntries = try? jsonDecoder.decode([UserEntries].self, from: data) {
allEntries = userEntries
}
allEntries.insert(userEntry, at: 0)
let jsonEncoder = JSONEncoder()
if let value = try? jsonEncoder.encode(allEntries) {
UserDefaults.standard.set(value, forKey: "allEntries")
UserDefaults.standard.synchronize()
}
let newViewController = storyboard?.instantiateViewController(withIdentifier: "tabViewController") as! UITabBarController
present(newViewController, animated: true, completion: nil)
}
And the problem with your controller is that you are saving only one entry to UserDefaults. Try to change your code to
let jsonDecoder = JSONDecoder()
if let data = UserDefaults.standard.data(forKey: "allEntries"),
let userEntries = try? jsonDecoder.decode([UserEntries].self, from: data) {
print(userEntries)
TableData = userEntries
}