SwiftUI NavigationLink immediately navigates back

Question

I am using SwiftUI to create NavigationLinks from rows to detail views in a NavigationView (similar to what is being done in the tutorial https://developer.apple.com/tutorials/swiftui/building-lists-and-navigation). However, when I test in my app, the NavgiationLink immediately navigates back from the detail view to the previous view after being tapped (the detail view only shows up for only a second).

Here's the code:

struct ItemsView: View {
    var body: some View {
        NavigationView {
            VStack {
                List {
                    ForEach(Query.items) { item in
                        NavigationLink(destination: ItemDetail(item: item)) {
                            ItemRow(item: item)
                        }
                    }
                }
                Spacer()
            }
            .navigationBarTitle(Text("Items"))
        }
    }
}

private struct ItemRow: View {
    var item: Item

    var body: some View {
        VStack(alignment: .leading) {
            Text(item.title)
                .font(.headline)
            item.completionDate.map({
                Text("Created \($0.shortDateTime)")
            })
            item.completionDate.map({
                Text("Active \(Date().offsetString(from: $0)) ago")
            })
        }
    }
}

struct ItemDetail: View {
    var item: Item

    var body: some View {
        VStack {
            Text("\(item.title)")
            Text("\(String(describing: item.creationDate))")
            Text("\(String(describing: item.completionDate))")
            Text("\(item.complete)")
        }
        .navigationBarTitle(Text("Item"), displayMode: .inline)
    }
}

The Query is done using Realm:

let realm = try! Realm()

class Query {
    static let items = realm.objects(Item.self)
}

It seems like this could be a problem with the Results<Item> object that is return from realm.objects(Item.self). When I tried it with static data using let items = [Item(), Item()] and then calling ForEach(items) { ... }, the navigation worked as expected.

score 3 · Answer 1 · answered Jan 09 '20 at 21:01

3

Fixed it by changing ForEach(Query.items) to ForEach(Array(Query.items)) to make the data static.

answered Jan 09 '20 at 21:01

bioround

375
2
12

What do you mean by making the data static? – Zorayr Jun 08 '20 at 23:51
The realm query returns a `Results` instance, which is kept up to date with changes that are made in the Realm. See https://realm.io/docs/swift/latest/#queries. I change the type of the `Results` instance to an `Array` to properly pass the object into SwiftUI the `ForEach` function. – bioround Jun 19 '20 at 02:42

E.Coms · Answer 2 · 2020-01-09T20:19:45.847

-1

The reason is ForEach(Query.items, id: \.self) missing an identifier. When you add one hashable or \.self . the List should work like a charm.

edited Jan 09 '20 at 20:19

answered Jan 09 '20 at 20:04

E.Coms

11,065
2
23
35

1

Thanks. I just tried that and the list works well but the navigationLink still immediately routes back to the original view after I tap it. It looks like its a problem with the `RealmSwift` `Results` object. When I tried it with static data the navigation worked as expected. – bioround Jan 09 '20 at 20:27
The issue still persists, see simple setup with using `id: \.self`, https://stackoverflow.com/questions/62275502/swiftui-navigationlink-programmatic-navigation-inside-onappear-immediately-navig – Zorayr Jun 09 '20 at 05:43

SwiftUI NavigationLink immediately navigates back

2 Answers2

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