Swift, fetch TableView from JSON and save it into array - ios

Question

i'm trying to do some simple things here, but i'm struggling a bit as i'm a beginner.
So basically i have a JSON file link to use to populate my tableview with 2 sections. Each cell have a "Favourite button".
i've tried many way to save my array with UserDefault with no luck.
What i wish to achieve:
When the "Favourite button" is pressed, i wish to move the cell to the other section
Save and retrieve those 2 array using UserDefault
I'm open to hear any suggestion also any other differs approach, as i'm sure there is some better one.
I will upload here some code, but also the link for the full project in Git so you can check better (https://github.com/Passeric/UserTableview.git)
I really appreciate any help.
The JSON i'm using:
{
"User": [
{
"Name": "John",
"Age": "34"
},{
"Name": "Sara",
"Age": "19"
}.......]}
My Struct:
class User: Codable {
let user: [UserDetails]
enum CodingKeys: String, CodingKey {
case user = "User"
}
init(user: [UserDetails]) {
self.user = user
}
}
class UserDetails: Codable {
let name: String
let age: String
enum CodingKeys: String, CodingKey {
case name = "Name"
case age = "Age"
}
init(name: String, age: String) {
self.name = name
self.age = age
}
}
And my ViewController:
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
var arrayDefault = [UserDetails]()
var arrayFavourite = [UserDetails]()
var sec: [Int:[UserDetails]] = [:]
var Default = UserDefaults.standard
#IBOutlet weak var myTableview: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
self.myTableview.dataSource = self
self.myTableview.delegate = self
DownloadJSON()
}
func numberOfSections(in tableView: UITableView) -> Int {
return 2
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
sec = [0 : arrayFavourite, 1 : arrayDefault]
return (sec[section]?.count)!
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let dataRef = arrayDefault[indexPath.row]
let cel: MyCell = tableView.dequeueReusableCell(withIdentifier: "MyCell", for: indexPath) as! MyCell
cel.NameLabel.text = dataRef.name
cel.AgeLabel.text = dataRef.age
let imgFav = UIImage(systemName: "star")
let b = imgFav?.withRenderingMode(.alwaysOriginal)
cel.FavButton.setImage(b, for: .normal)
return cel
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
}
func DownloadJSON() {
let urlll = URL(string: "https://pastebin.com/raw/Wufivqmq")
guard let downloadURL = urlll else { return }
URLSession.shared.dataTask(with: downloadURL) { data, urlResponse, error in
guard let data = data, error == nil, urlResponse != nil else {
print("something is wrong")
return
}
print("downloaded")
do
{
let decoder = JSONDecoder()
let downloadeduser = try decoder.decode(User.self, from: data)
self.arrayDefault.removeAll()
self.arrayDefault.append(contentsOf: downloadeduser.user)
DispatchQueue.main.async {
print("data saved")
self.myTableview.reloadData()
}
} catch {
print(error)
}
}.resume()
}
#IBAction func RefreshButton(_ sender: Any) {
// Here i wish to refresh the table view (so the current saved array) with the updated JSON
// For example if i update the "Age" in the original JSON
// But i don't want to lose the user preference for the "Favourite"
}
}
As you can see is not a big deal thing, but i can't figure out how to properly save and retrive the array, and then move the cell (by the index path) to the other array.
This is the link for the full project: https://github.com/Passeric/UserTableview.git
Thanks again to anyone who will help.❤️

Answer 1

I would make a few changes:
Clean up your data model. Currently you are storing the data as both two arrays and a dictionary. There are minor pros and cons to each approach, but in the grand scheme of things it doesn't really matter which one you use, just pick one. Personally, as a beginner, I would go with two arrays.
Don't change your data model in the data source. Currently you are creating the sec dictionary in the tableView:numberOfRowsInSection function. If you want to keep using sec then create it as the same time you load the data initially. Or, as mentioned above, just remove sec completely.
Assuming you've made the above changes, moving a user to the favorites section is as simple as removing the user from the default list, adding it to the favorites list, and telling the list that the data has changed:
func makeFavorite(index:IndexPath) {
let user = arrayDefault[index.row]
arrayDefault.remove(at: index.row)
arrayFavourite.append(user)
//This updates the entire list. You might want to use moveRow(at:to:) in order to animate the change
tableView.reloadData()
}
When it comes to converting your data model to/from json, you're already most of the way there by conforming to Codable. To load from json:
if let jsonData = UserDefaults.standard.string(forKey: "userKey").data(using: .utf8) {
let decoder = JSONDecoder()
if let user = try? decoder.decode(User.self, from: jsonData) {
//Do something with user here...
}
}
And to output to json:
let encoder = JSONEncoder()
if let data = try? encoder.encode(user),
let jsonString = String(decoding: data, as: .utf8) {
UserDefaults.standard.setValue(jsonString, forKey: "userKey")
}
Do the same thing with the list of favorites (using a different key).