How to use EnvironmentObject correctly

Question

Created Sep ’22

Replies 2

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Hi, I just learned SwiftUI and am still confused on how using @EnvironmentObject correctly. should I declare @StateObject to use @EnvironmentObject on later views or not? Or maybe I can directly declare the used file in the .environmentObject property?

like this?:

struct ContentView: View {
    @StateObject var viewModel = ViewModel()
    
    var body: some View {
        NavigationView {
              // Content
        }
        .environmentObject(viewModel)
    }
}

or this?:

struct ContentView: View {
    let viewModel = ViewModel()
    
    var body: some View {
        NavigationView {
              // Content
        }
        .environmentObject(viewModel)
    }
}

or maybe this?:

struct ContentView: View {
    var body: some View {
        NavigationView {
              // Content
        }
        .environmentObject(ViewModel())
    }
}

or these 3 actually works fine for different situations?

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Answer 1

BabyJ OP

Sep ’22

Accepted Answer

The first option is the recommended way of doing it.

Create the ObservableObject class as an @StateObject property first, and only once
Pass it into the environment, with environmentObject(_:)
Access the class from subviews using @EnvironmentObject

2

Answer 2

kyubeez OP

Sep ’22

Apparently I missed this article https://developer.apple.com/documentation/swiftui/managing-model-data-in-your-app smh (I think I’ve read it before but didn’t understand well)

0