Hi,
I have a working program with categories, lists and detail views. All connected via NavigationLink inside a NavigationStack.
It looks a bit strange on an iPad, so I replaced the NavigationStack with a NavigationSplitView. The categories went into the sidebar and the lists into the content section.
The detail section of the NavigationSplitView is empty and it still works. Is that the correct behavior? I don't mind it, because it works.
example code:
var body: some View {
NavigationSplitView {
List(selection: $listSelection) {
Section("Section 1") {
NavigationLink(value: EnumValue.V1) {
CardView("Card 1")
}
NavigationLink(value: EnumValue.V2) {
CardView("Card 2")
}
NavigationLink(value: EnumValue.V3) {
CardView("Card 3")
}
}
Section("Section 2") {
NavigationLink(value: EnumValue.V4) {
CardView("Card 4")
}
NavigationLink(value: EnumValue.V5) {
CardView("Card 5")
}
}
}
.scrollIndicators(.hidden)
.navigationTitle("Detail Empty")
} content: {
if let mt = listSelection {
switch mt {
case .V1:
ListView1()
case .V2:
ListView2()
case .V3:
ListView3()
case .V4:
ListView4()
case .V5:
ListView5()
}
}
} detail: {
// empty
}
}
In each ListView, I assign the ID to the EditorView so that the EditorView is updated.
.navigationDestination(for: ViewListTransfer.self) { vl in
switch vl {
case .trend(bp: let bp):
EditorView(value: bp)
.id(bp.Id)
case .trendNew:
EditorView(val: nil)
}
}
It seems to work because everything is linked via NavigationLinks, but it does look strange that the detail section is empty. The details section is mandatory; therefore, it cannot be omitted.
Is this behavior something for a bug report?
Christian
Hello Christian,
Thanks for using the Developer Forums!
Even though your detail: contains no additional code, SwiftUI adds in an EmptyView for you. The detail parameter is a @ViewBuilder closure, and a builder with no statements returns EmptyView. That makes the detail column a blank placeholder until something is selected.
The detail still fills in because of how NavigationLink works in a split view. A link in the sidebar or content column presents its destination in the next column. When you tap a row in your content list, that link's destination replaces the empty placeholder in the detail column, so the closure doesn't need any content of its own.
If you want something visible before the first selection, put it in detail: as a placeholder, for example ContentUnavailableView.
For more information, see NavigationSplitView, which you can also quickly see by Option + Left Click on a NavigationSplitView in Xcode to see the same information, which can be helpful for quickly explaining things like this.
You might also find these resources helpful:
The SwiftUI cookbook for navigation
Travis
