Saving a list using Codable or userDefaults-CodePudding

Can someone help me to save the list in this code using Codable or another methods. I am not able to use the UserDefaults in the code. Can anyone help me how to use save the lists so that when ever, I re-open my app, the list is still there. Thanks.

import SwiftUI
struct MainView: View {

    @State var br = Double()
    @State var loadpay = Double()
    @State var gp : Double = 0
    @State var count: Int = 1
    @State var listcheck = Bool()
    @StateObject var taskStore = TaskStore()
 @State var name = String()
    var userCasual = UserDefaults.standard.value(forKey: "userCasual") as? String ?? ""
    func addNewToDo() {
         taskStore.tasks.append(Task(id: String(taskStore.tasks.count   1), toDoItem:  "load \(count)", amount: Double(gp)))
   }
    func stepcount() {
       
     count  = 1
        
    }
    var body: some View {
        VStack {
            TextField("Name", text: $name)
            HStack {
            Button(action: { gp  = loadpay }) {
                Text("Add Load")
            }
            Button(action: {
                addNewToDo()
            }) {
                Text("Check")
            }
        }
            Form {
                ForEach(self.taskStore.tasks) {
                    task in
                    Text(task.toDoItem)
                }
            }
        }
        Button(action: {
            UserDefaults.standard.set(name, forKey: "userCasual")})
        {Text("Save")}

}

}
struct Task : Identifiable {
    var id = String()
    var toDoItem = String()
    var amount : Double = 0
}

class TaskStore : ObservableObject {
    @Published var tasks = [Task]()
}

CodePudding user response：

In Task adopt Codable

struct Task : Codable, Identifiable {
    var id = ""
    var toDoItem = ""
    var amount = 0.0
}

In TaskStore add two methods to load and save the tasks and an init method

class TaskStore : ObservableObject {
    @Published var tasks = [Task]()
    
    init() {
        load()
    }
    
    func load() {
        guard let data = UserDefaults.standard.data(forKey: "tasks"),
              let savedTasks = try? JSONDecoder().decode([Task].self, from: data) else { tasks = []; return }
        tasks = savedTasks
    }
    
    func save() {
        do {
            let data = try JSONEncoder().encode(tasks)
            UserDefaults.standard.set(data, forKey: "tasks")
        } catch {
            print(error)
        }
    }
}

In the view call taskStore.save() to save the data.

However: For large data sets UserDefaults is the wrong place. Save the data in the Documents folder or use Core Data.

Side note: Never use value(forKey:) in UserDefaults, in your example there is string(forKey:)

CodePudding user response：

You should take a look at the @AppStorage property wrapper. Here is a great article written by Paul Hudson who is a great resource when you're learning iOS.

UserDefaults isn't the best way to store persistent information though. Once you get a bit more comfortable with Swift and SwiftUI, you should look into CoreData for storing your data across sessions.