swiftui-data-flow-environmentObject.swift

struct EnvironmentContainerView: View {
    @State var bookStore = BookStore()
    
    var body: some View {
        EnvChildView()
            .environmentObject(bookStore) // <- `EnvironmentObject` as a view modifier
    }
}

struct EnvChildView: View {
    
    var body: some View {
        EnvChildChildView()
    }
}

struct EnvChildChildView: View {
    @EnvironmentObject var bookStore: BookStore // <- `EnvironmentObject` as a property wrapper
    
    var body: some View {
        Text(bookStore.books[0].name) // "The Great Influenza"
    }
}