How to use Bind an Associative Swift enum? - swift

Question

I have a GroupView that accepts a binding as a parameter because I want the GroupView to modify the data in the enum.
Can some help me on how to accomplish this?
import SwiftUI
struct ContentView: View {
#ObservedObject var viewModel = ViewModel()
var body: some View {
VStack {
GroupView(group: /* What do i put here? */) // <----------------
}
}
}
struct GroupView: View {
#Binding var group: Group
var body: some View {
Text("Hello World")
}
}
class ViewModel : ObservableObject {
#Published var instruction: Instruction!
init() {
instruction = .group(Group(groupTitle: "A Group struct"))
}
}
enum Instruction {
case group(Group)
}
struct Group { var groupTitle: String }

Answer 1

Well, this certainly will work... but probably there's a better approach to your problem. But no one is in a better position than you, to determine that. So I'll just answer your question about how to pass a binding.
struct ContentView: View {
#ObservedObject var viewModel = ViewModel()
var body: some View {
VStack {
GroupView(group: viewModel.groupBinding)
}
}
}
class ViewModel : ObservableObject {
#Published var instruction: Instruction!
init() {
instruction = .group(Group(groupTitle: "A Group struct"))
}
var groupBinding: Binding<Group> {
return Binding<Group>(get: {
if case .group(let g) = self.instruction {
return g
} else {
return Group(groupTitle: "")
}
}, set: {
self.instruction = .group($0)
})
}
}