Shell/property injection: know when it's finished

[softlion]

Hello mauiers,
it would be nice to have a method called when property injection has finished. So custom initialization can start.

Something like:

[QueryProperty(nameof(Item1), "item1")]
[QueryProperty(nameof(Item2), "item2")]
[QueryInitialized(nameof(MyMethod))]
public class MyModel
{
    public string? Item1 { get; set; }
    public string? Item2 { get; set; }

    private void MyMethod()
    {
        //The object knows that Item1 and Item2 have been initialized.
    }
}

What do you think ?

The current workaround is to forward OnParentSet from the view. But this has a side effect of displaying an uninitialized view that may flash to its initialized state.

protected override void OnParentSet()
{
    base.OnParentSet();
    ((MyModel)BindingContext).MyMethod();
}

[Jared-Aus]

I'm not a fan of shell navigation due to complexities like these, but I think in your case IQueryAttributable might be a reasonable substitute. It won't solve the likely problem of your view model being in a useless/empty state when the page is first presented however.

[softlion]

Ok that won't resolve my issue, but you can't know :)

I'm reusing a viewmodel between 2 pages. One page is accessed by a tab. So it can't have any query param at all, as tab pages don't have that.
The other page is a normal child page that does have ome query params.

My issue was to have a common entry point in the viewmodel that is triggered after the optional query params have been set, or not set (ie: the tab is displayed for the 1st time).

But that's a good point !