SwiftUI: NavigationDestinationLink deprecated
After spending some time with NavigationLink(destination:isActive)
, I am liking it a lot more than the old NavigationDestinationLink
. The old view was a little confusing, while the new approach seems much more elegant. And once I figure out how to push without animations, it would make state restoration at application launch very easy.
There is one problem though, a big and ugly bug. :-(
Pushing a view programatically works fine, and popping it programatically does too. The problem starts when we use the BACK button in the pushed view which behaves oddly every other time. The first time the view is popped, the view pops and pushes again immediately. The second time around it works fine. Then the third time it starts all over again.
I have created a bug report (number here). I recommend you do the same and reference my number too, to help Apple group them together and get more attention to the problem.
I designed a workaround, that basically consists of replacing the default Back button, with our own:
class Model: ObservableObject {
@Published var pushed = false
}
struct ContentView: View {
@EnvironmentObject var model: Model
var body: some View {
NavigationView {
VStack {
Button("Push") {
// view pushed programmatically
self.model.pushed = true
}
NavigationLink(destination: DetailView(), isActive: $model.pushed) { EmptyView() }
}
}
}
}
struct DetailView: View {
@EnvironmentObject var model: Model
var body: some View {
Button("Bring me Back (programatically)") {
// view popped programmatically
self.model.pushed = false
}
// workaround
.navigationBarBackButtonHidden(true) // not needed, but just in case
.navigationBarItems(leading: MyBackButton(label: "Back!") {
self.model.pushed = false
})
}
}
struct MyBackButton: View {
let label: String
let closure: () -> ()
var body: some View {
Button(action: { self.closure() }) {
HStack {
Image(systemName: "chevron.left")
Text(label)
}
}
}
}
To improve the workaround without replacing the back button with a custom one, you can use the code above :
NavigationLink(destination: Test().onAppear(perform: {
self.editPushed = nil
}), tag: 1, selection: self.$editPushed) {
Button(action: {
self.editPushed = 1
}) {
Image(systemName: "plus.app.fill")
.font(.title)
}
}
The onAppear block will erase the selection value preventing to display the detail view twice