Background + Example Code

Let's say I have a SwiftUI ViewModel like so:

class ViewModel: ObservableObject {
    @Published var strs: [String] = []
    

    func fetchStrs() async {
    // This function would have fetching logic for whatever type the model stored
    // Here, we are just storing some strings for simplicity.
    // We wait one second to mimic an API Call
    try await Task.sleep(nanoseconds: UInt64(1 * Double(NSEC_PER_SEC)))
    self.strs = ["Hello", "World", "!"]
    }
}

Since the ViewModel would have that function to fetchStrs from the API, we could get this information in two ways. I could either use a Task and get the Strings in the initializer like so:

init() {
    Task {
        await fetchStrs()
    }
}

Or I could use a .onAppear method in my View (.task does basically the same thing with a Task in onAppear) like so:

struct ExampleView: View {
    @StateObject var viewModel = ViewModel()
    var body: some View {
        //... List of strings here
        .task {
            viewModel.fetchStrs()
        }
    }
}

Question

As seen above, I have two major ways to get dynamic data from an API at runtime. However, which one should I use? Are there any sort of Swift style conventions that lean toward one or the other? I recognize that .task or .onAppear may be later than expected in some cases, but that shouldn't matter because the method is asynchronous. Is there a correct way of getting these data, or is it developer preference?

posted almost 3 years ago

CC BY-SA 4.0

3y ago

MrDevel0per‭

11 reputation 1 0 2 3