Make SwiftUI document available as EnvironmentObject - swift

Question

I am reading a FileDocument using SwiftUI. This document is available though a binding to the top-most view:
struct ContentView: View {
#Binding var document: SomeDocument
var body: some View {
Text(self.document.someString)
NestedChildViews().environmentObject(self.document)
} 
}
Is there are a way to turn this #Binding of the document into an #EnvironmentObject to make it available to all nested views? Simply replacing #Binding with #EnvironmentObject will not work, since FileDocument is a struct.
Property type 'SomeDocument' does not match that of the 'wrappedValue' property of its wrapper type 'EnvironmentObject'
Creating an in-between ObservableObject that is created as a #StateObject inside ContentView won't work, since it has to be initiated before the Binding to document is available:
struct ContentView: View {
#Binding var document: SomeDocument
#StateObject var sharedState = SomeSharedState(document: self.document) // won't work
}
What would be the best way to handle this in-between a document and a series of nested views without passing bindings between all levels of them?

Answer 1

You should initialize your #StateObject from within the view's init, since you are passing in the document into the init:
struct ContentView: View {
#Binding var document: SomeDocument
#StateObject var sharedState: SomeSharedState
init(document: Binding<SomeDocument>) {
_document = document
_sharedState = StateObject(wrappedValue: SomeSharedState(document: document.projectedValue))
}
var body: some View {
Text(document.someString)
.environmentObject(sharedState)
/* TEST TO SHOW IT WORKS
.onAppear {
DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
document = SomeDocument(someString: "New!")
}
}
*/
}
}
class SomeSharedState: ObservableObject {
#Published var document: Binding<SomeDocument>
init(document: Binding<SomeDocument>) {
_document = Published(initialValue: document)
}
}