MVVM and passing over optinal value to the viewModel

Question

I am trying to get a MVVM approach to work for my swiftui app but I have a problem where a optional variabel does not seem to get passed over correct.

So the home view you can click either on "new" or "edit", on edit I want to pass the value over, the code for this screen: Button:

Button {
        selectedTag = tag
        isShowingEdit.toggle()
} label: {
         Image(systemName: "pencil")
         .font(Font.system(size: 30, weight: .bold))
         .foregroundColor(.gray)
}

Navigationlink:

  NavigationLink(destination: TagsCreatingView(viewModel: TagCreateViewModel(tag: selectedTag)), isActive: $isShowingEdit) { EmptyView() }

The TagCreateViewModel init looks as following:

  init(tag: TagMO?) {

    if let tag = tag {
    self.tag = tag
        title = tag.title
        selectedColor = Int(tag.color)
    }

If I do a print on selectedTag when I click the button it has the correct value, but over inte the viewModel it will be nil. Also if I click the edit button twice it works as planned and tag is not nil ( by twice I mean click edit, on the other screen click cancel then edit again..)

score 0 · Answer 1 · answered Aug 10 '21 at 06:37

0

The problem was that inside the destination view had

@StateObject var viewModel: TagCreateViewModel

Changing it to @ObservedObject var viewModel: TagCreateViewModel

Solved it since the ownership got put correct :9

answered Aug 10 '21 at 06:37

Peter

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MVVM and passing over optinal value to the viewModel

1 Answers1