No ObservableObject

Question

Created May ’20

Replies 6

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Participants 5

Studing SwiftUI in Apple's HandlingUserInput, I'm blocked in this error:
No ObservableObject of type UserData found. A View.environmentObject(_:) for UserData may be missing as an ancestor of this view.
The code is:

final class UserData: ObservableObject  {
    @Published var showFavoritesOnly = false
    @Published var landmarks = landmarkData
}

struct LandmarkList: View {
    @EnvironmentObject var userData: UserData

    var body: some View {
        NavigationView {
            List(landmarkData) { landmark in
               if !self.userData.showFavoritesOnly || landmark.isFavorite {
                    NavigationLink(destination: LandmarkDetail(landmark: landmark)) {
                        LandmarkRow(landmark: landmark)
                    }
               }
            }
            .navigationBarTitle(Text("Landmarks"))
        }
    }
}
struct LandmarkList_Previews: PreviewProvider {
    static var previews: some View {
            LandmarkList()
                 .environmentObject(UserData())
    }
}

".environmentObject(UserData())" is present in the preview.

"@EnvironmentObject var userData: UserData" in the View.

But the use of userData (if !self.userData.showFavoritesOnly) cause the fatal error.

Can someone help me in undertanding how to proceed?

Answered by OOPer in 418584022

Have you followed Step 4 - Section 5 of the tutorial?

> In

SceneDelegate.swift

, add the

environmentObject(_:)

modifier to the

LandmarkList

.

".environmentObject(UserData())" is present in the preview.

Preview is just used for previewing, you need to put `environmenObject(UserData())` somewhere in an actual app.

Boost

Answer 1

Claude31 OP

May ’20

It is Landmark project: it is flawed as it is not updated for new versions of XCode

Search for Landmark in the forum, you will get a lot of threads and some solutions.

Note: you should move this thread to SwiftUI.

0

Answer 2

OOPer OP

May ’20

Accepted Answer

Have you followed Step 4 - Section 5 of the tutorial?

> In

SceneDelegate.swift

, add the

environmentObject(_:)

modifier to the

LandmarkList

.

".environmentObject(UserData())" is present in the preview.

Preview is just used for previewing, you need to put `environmenObject(UserData())` somewhere in an actual app.

1

Answer 3

Luca_65 OP

May ’20

Thank you Claude31and OOPer,

I did a mistake adding environmentObject into SceneDelegate.swift, revising it I saw the error.

0

Answer 4

JLS31 OP

Jan ’22

Hello

how do you manage this issue with Xcode 13.2.1 as SceneDelegate.swift doesn't appear anymore in the file list ?

SwiftUI/EnvironmentObject.swift:70: Fatal error: No ObservableObject of type ToDoStorage found. A View.environmentObject(_:) for ToDoStorage may be missing as an ancestor of this view.

0

Answer 5

Claude31 OP

Jan ’22

You'd better start a new thread than ask new question in another (closed) one. And reference this older thread in your post.

0

Answer 6

Yash_patil OP

Jul ’22

Add the .environmentObject(UserData()) at the @main point in WindowGroup in the View

For eg: @main

struct YourApp: App {

@StateObject var userData = UserData()

var body: some Scene {

WindowGroup

{

YourMainView().environmentObject(userdata)

}

Also Try replacing the if !self.userData.showFavoritesOnly with if userData.showFavouritesOnly != false or true // According to your condition

0