I have an app and want to add an edit page for the detailView. To do that I build a simulair view like the add view. It's something like this:

@State private var name = ""

var body: some View {
    Form {
        TextField("Name", text: $name)
    }
}

And off course it has some functions and such but that is inrelivant i think.

What I want is that I'm able to edit the text like in your iphones contact app. So the data/text is already in the textfield, ready to be edited.

I have to mention that the data is stored in CoreData.

The Edit view needs a property to store the Core Data entity so you can fill the view with the appropriate data from the entity. Core Data uses classes so you would use the @StateObject property wrapper.

@StateObject var model: Model

Where Model is the name of your Core Data entity.

Now you can fill the text field from the entity.

TextField("Name", text: $model.name)

You'll also have to pass the entity to the Edit view when making the call to show the Edit view.

If I do that i get "Cannot convert value of type 'Binding<String?>' to expected argument type 'Binding<String>'"

Give your optional a default value:

TextField("Name", text: $model.name ?? "text")

That doesn't work. You want to replace a binding to a empty string. You can't use this somewhere else to save it.

Error messages: Cannot convert value of type 'String' to expected argument type 'Binding<String?>' Cannot convert value of type 'Binding<String?>' to expected argument type 'Binding<String>'

Does the below work?

struct DetailView: View {

    @StateObject var model: Marteen
    @State private var name: String = "Text"

    var body: some View {
        TextField("Name", text: $name).onChange(of: name) { newValue in
            model.name = newValue
        }
    }
}

In my case this gives a empty textfield.

struct ContactDetailEditView: View {

    @StateObject var model: ContactEntity

    @State private var firstName: String = ""

    var body: some View {
        TextField("First Name", text: $firstName)
            .onChange(of: firstName) { newValue in
            contact.firstName = newValue
        }
    }
}

Why you are using ?

contact.firstName = newValue

Whereas you made an instance of a

@StateObject var model: ContactEntity

it should be

model.firstName = newValue

I tried the code I sent you before and it works, everytime you type in the textfield the model.name is updated. Add a print in the OnChange to verify.

Because i made a type with re typing it here.

But it doesn't change enything.

I just found a solution for it.

struct ContactDetailEditView: View {

    @StateObject var model: ContactEntity

//    let contact: ContactEntity

    @State private var firstName: String = ""

    var body: some View {

        TextField("First Name", text: $firstName)
            .onAppear {
                DispatchQueue.main.asyncAfter(deadline: .now()){
                    firstName = model.firstName ?? ""
                }
            }
            .onChange(of: firstName) { newValue in
            model.firstName = newValue
        }
    }
}

credits to: link