Coordinator SwiftUI

Simple coordinator with router

Navigation types

• Change tab TabView
• Navigation by NavigationPath
• Present sheet and with dynamically height sheet
• Present full screen cover
• Alert with error
• Route from widget through coordinator

Router

CoordinatorSwiftUI/CoordinatorSwiftUI/Coordinator/NavigationRouter.swift

Lines 10 to 17 in da80bda

	protocol NavigationRouter: Hashable, Identifiable {
	associatedtype V: View
	var style: TransitionStyle? { get }
	@ViewBuilder
	func view() -> V
	}

Coordinator

CoordinatorSwiftUI/CoordinatorSwiftUI/Coordinator/Coordinator.swift

Lines 10 to 58 in da80bda

	class Coordinator<Router: NavigationRouter>: ObservableObject {
	@Published var path = NavigationPath()
	@Published var sheet: Router?
	@Published var cover: Router?
	@Published var hasError: Bool = false
	var error: LocalizedError?
	func push(_ page: Router) {
	path.append(page)
	}
	func pop() {
	path.removeLast()
	}
	func popToRoot() {
	path.removeLast(path.count)
	}
	func present(sheet: Router) {
	self.sheet = sheet
	}
	func dismissSheet() {
	sheet = nil
	}
	func present(cover: Router) {
	self.cover = cover
	}
	func dismissCover() {
	cover = nil
	}
	func presentAlert(error: LocalizedError) {
	self.error = error
	hasError = true
	}
	@ViewBuilder
	func build(_ route: Router) -> some View {
	route.view()
	}
	}

TabCoordinator

CoordinatorSwiftUI/CoordinatorSwiftUI/TabCoordinator/TabCoordinator.swift

Lines 10 to 27 in da80bda

	class TabCoordinator<Router: NavigationRouter>: ObservableObject {
	@Published var tab: Router
	init(tab: Router) {
	self.tab = tab
	}
	func change(_ route: Router) {
	self.tab = route
	}
	@ViewBuilder
	func build(_ route: Router) -> some View {
	route.view()
	.tag(route)
	}
	}

Example

Navigation in App	Navigation from Widget
CoordinatorDemonstration.mp4	Widget.route.mov

Coordinator

CoordinatorSwiftUI/CoordinatorSwiftUI/Fruits/Coordinator/FruitsCoordinatorView.swift

Lines 10 to 30 in da80bda

	struct FruitsCoordinatorView: View {
	@StateObject var coordinator: Coordinator<FruitsRouter>
	var body: some View {
	NavigationStack(path: $coordinator.path) {
	coordinator.build(.fruits)
	.navigationTitle("Fruits 🛒")
	.navigationDestination(for: FruitsRouter.self) { route in
	coordinator.build(route)
	}
	.sheet(item: $coordinator.sheet) { route in
	coordinator.build(route)
	}
	.fullScreenCover(item: $coordinator.cover) { route in
	coordinator.build(route)
	}
	}
	.environmentObject(coordinator)
	}
	}

Router

CoordinatorSwiftUI/CoordinatorSwiftUI/Fruits/Router/FruitsRouter.swift

Lines 10 to 37 in da80bda

	enum FruitsRouter: NavigationRouter {
	case fruits
	case cherry(count: Int)
	case lemon(count: Int)
	case watermelon(count: Int)
	var id: Self {
	return self
	}
	var style: TransitionStyle? {
	return nil
	}
	@ViewBuilder
	func view() -> some View {
	switch self {
	case .fruits:
	FruitsView()
	case .cherry(let count):
	CherryView(count: count)
	case .lemon(let count):
	LemonView(count: count)
	case .watermelon(let count):
	WatermelonView(count: count)
	}
	}
	}

Used materials

• Coordinator https://betterprogramming.pub/an-introduction-to-coordinator-pattern-in-swiftui-38e5b02f031f

• Sheet with dynamic height https://serialcoder.dev/text-tutorials/swiftui/presenting-sheets-of-various-heights-in-swiftui/ https://www.en.techgaku.com/get-frame-size-of-swiftui-view-dynamically/

• Navigation examples https://bignerdranch.com/blog/the-different-forms-of-navigation-in-swiftui/

• Alert https://www.hackingwithswift.com/quick-start/swiftui/how-to-show-an-alert