Awesome
Navigation Backport
This package uses the navigation APIs available in older SwiftUI versions (such as NavigationView
and NavigationLink
) to recreate the new NavigationStack
APIs introduced in WWDC22, so that you can start targeting those APIs on older versions of iOS, tvOS, macOS and watchOS. When running on an OS version that supports NavigationStack
, NavigationStack
will be used under the hood.
✅ NavigationStack
-> NBNavigationStack
✅ NavigationLink
-> NBNavigationLink
✅ NavigationPath
-> NBNavigationPath
✅ navigationDestination
-> nbNavigationDestination
✅ NavigationPath.CodableRepresentation
-> NBNavigationPath.CodableRepresentation
You can migrate to these APIs now, and when you eventually bump your deployment target, you can remove this library and easily migrate to its SwiftUI equivalent. NavigationStack
's full API is replicated, so you can initialise an NBNavigationStack
with a binding to an Array
, with a binding to an NBNavigationPath
binding, or with no binding at all.
Example
<details> <summary>Click to expand an example</summary>import NavigationBackport
import SwiftUI
struct ContentView: View {
@State var path = NBNavigationPath()
var body: some View {
NBNavigationStack(path: $path) {
HomeView()
.nbNavigationDestination(for: NumberList.self, destination: { numberList in
NumberListView(numberList: numberList)
})
.nbNavigationDestination(for: Int.self, destination: { number in
NumberView(number: number)
})
.nbNavigationDestination(for: EmojiVisualisation.self, destination: { visualisation in
EmojiView(visualisation: visualisation)
})
}
}
}
struct HomeView: View {
var body: some View {
VStack(spacing: 8) {
NBNavigationLink(value: NumberList(range: 0 ..< 100), label: { Text("Pick a number") })
}.navigationTitle("Home")
}
}
struct NumberList: Hashable {
let range: Range<Int>
}
struct NumberListView: View {
let numberList: NumberList
var body: some View {
List {
ForEach(numberList.range, id: \.self) { number in
NBNavigationLink("\(number)", value: number)
}
}.navigationTitle("List")
}
}
struct NumberView: View {
@EnvironmentObject var navigator: PathNavigator
let number: Int
var body: some View {
VStack(spacing: 8) {
Text("\(number)")
NBNavigationLink(
value: number + 1,
label: { Text("Show next number") }
)
NBNavigationLink(
value: EmojiVisualisation(emoji: "🐑", count: number),
label: { Text("Visualise with sheep") }
)
Button("Go back to root", action: { navigator.popToRoot() })
}.navigationTitle("\(number)")
}
}
struct EmojiVisualisation: Hashable {
let emoji: String
let count: Int
var text: String {
Array(repeating: emoji, count: count).joined()
}
}
struct EmojiView: View {
let visualisation: EmojiVisualisation
var body: some View {
Text(visualisation.text)
.navigationTitle("Visualise \(visualisation.count)")
}
}
</details>
Additional features
As well as replicating the standard features of the new NavigationStack
APIs, some helpful utilities have also been added.
Navigator
A Navigator
object is available through the environment, giving access to the current navigation path. The navigator can be accessed via the environment, e.g. for a NBNavigationPath-backed stack:
@EnvironmentObject var navigator: PathNavigator
Or for a stack backed by an Array, e.g. [ScreenType]
:
@EnvironmentObject var navigator: Navigator<ScreenType>
As well as allowing you to inspect the path elements, the navigator can be used to push new screens, pop, pop to a specific screen or pop to the root.
Navigation functions
Whether interacting with an Array
, an NBNavigationPath
, or a Navigator
, a number of utility functions are available for easier navigation, such as:
path.push(Profile(name: "John"))
path.pop()
path.popToRoot()
path.popTo(Profile.self)
Note that, if you want to use these methods on an Array
, ensure the Array
's Element
conforms to NBScreen
, a protocol that inherits from Hashable without adding any additional requirements. This avoids polluting all arrays with APIs specific to navigation.
Deep-linking
Before NavigationStack
, SwiftUI did not support pushing more than one screen in a single state update, e.g. when deep-linking to a screen multiple layers deep in a navigation hierarchy. NavigationBackport
works around this limitation: you can make any such path changes, and the library will, behind the scenes, break down the larger update into a series of smaller updates that SwiftUI supports if necessary, with delays in between. For example, the following code that pushes three screens in one state update will push the screens one by one if needed:
path.append(Screen.orders)
path.append(Screen.editOrder(id: id))
path.append(Screen.confirmChanges(orderId: id))
This only happens when necessary: on versions of SwiftUI that support NavigationStack
, all three screens will be pushed successfully in one update.
Support for iOS/tvOS 13
This library targets iOS/tvOS versions 14 and above, since it uses StateObject
, which is unavailable on iOS/tvOS 13. However, there is an ios13
branch, which uses SwiftUIBackports' backported StateObject, so that it works on iOS/tvOS 13 too.
FlowStacks
Want to further upgrade your navigation APIs? FlowStacks enhances these familiar APIs to allow you to additionally drive sheet and full-screen cover navigation from a single unified interface.