CODEWITHSUNDEEP
swiftproperty-wrapper
Arun
Arun

Reputation: 136

Swift @ObservedObject initialize with another property

EDIT added the source code showing declaration of the variables

I am trying to initialize a view model property which is an @ObservedObject @ObservedObject private var viewmodel : ExpenseListViewModel

I want to initialize the view model with a repostitory which is going to accept the ManagedObjectContext as a parameter in the constructor

Since viewmodel has a prperty wrapper it is not allowing to create it as a computed property either.

when i tried to initialize the Repository and viewmodel in the init i get an self is used before being initialized

struct ContentView: View {
    @Environment(\.managedObjectContext) private var moc
    private (set) var repo: Repository
    @ObservedObject  private var viewmodel : ExpenseListViewModel 
    init() {
        //let repository = CoreDataRepository(Context: moc)
        repo = CoreDataRepository(Context: self.moc)
        self.viewmodel = .init(repository: repo)
    }
    var body: some View {
        Text(viewmodel.Expenses[0].Name ).onAppear(perform: viewmodel.getExpenses )
    }
}

Upvotes: 1

Views: 1157

Answers (1)

Asperi
Asperi

Reputation: 257703

The @Environment is not available on init call phase, it is injected later. So here is possible solution:

struct ContentView: View {
    @Environment(\.managedObjectContext) private var moc

    var body: some View {
        InternalContentView(context: moc) // context is ready in body
    }

    struct InternalContentView: View {
        @ObservedObject private var viewmodel: ExpenseListViewModel

        init(context: NSManagedObjectContext) {
            self.viewmodel = .init(repository: CoreDataRepository(Context: context))
        }

        var body: some View {
            Text(viewmodel.Expenses[0].Name ).onAppear(perform: viewmodel.getExpenses )
        }
    }
}

Upvotes: 3

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