Managing TabView selections in SwiftUI

TabSelect.swift

import SwiftUI

protocol TabSelectable {
    associatedtype Tab
    func shouldSelect(_ tab: Tab) -> Bool
}

@propertyWrapper
struct TabSelection<Value: Hashable> {
    
    init(wrappedValue: Value) {
        _selection = wrappedValue
    }
    
    var _selection: Value
    private var selectable: ((Value) -> Bool)?
    
    mutating func register<S>(_ selectable: S) where S : TabSelectable, Value == S.Tab {
        self.selectable = selectable.shouldSelect
    }
    
    var wrappedValue: Value {
        get { _selection }
        set {
            guard selectable?(newValue) ?? true else {
                return
            }
            
            _selection = newValue
        }
    }
}

enum TabName: Hashable {
    case home
    case news
    case more
}

class TabSelect: ObservableObject, TabSelectable {
    
    init() {
        _selection.register(self)
    }

    func shouldSelect(_ tab: TabName) -> Bool {
        guard tab != .more else {
            showModal.toggle()
            return false
        }
        
        return true
    }
        
    @TabSelection var selection = Tab.home {
        willSet {
            objectWillChange.send()
        }
    }
    
    var showModal = false
}

struct ContentView: View {
    
    @StateObject var tabSelect = TabSelect()
    
    var body: some View {
        TabView(selection: $tabSelect.selection) {
            Text("Home")
                .tabItem {
                    Text("Home")
                }
                .tag(TabName.home)
            
            Text("News")
                .tabItem {
                    Text("News")
                }
                .tag(TabName.news)
            
            Text("More")
                .tabItem {
                    Text("More")
                }
                .tag(TabName.more)
        }
        .sheet(isPresented: $tabSelect.showModal) {
            Text("Modal")
        }
    }
}