Handle Loading Indicator state pre/post API call

[alexgeorghiou]

Hello,

I would appreciate your input on what would the best way be to handle a dispatch of a "show Loading Indicator" action , preceding an API call, then another Dispatch to hide the indicator. The hiding of the Loader takes 2-3 more seconds to complete, after API call returns a response. The problem I am facing seems to happen because the API call is awaited,

Loading Indicator with bool IsVisible { get { return ViewState.Value.Loading; } set { } } that subscribes to ViewStateLoadingAction on its OnInitialized SubscribeToAction((ViewStateLoadingAction action) => InvokeAsync(StateHasChanged));

Reducer that handles new state

 [ReducerMethod]
 public static ViewState OnViewStateLoadingUI(ViewState state, ViewStateLoadingAction action)
 {
     return state with
     {
         Loading = action.Loading
     };
 }

and Effect that dispatches action to show Loader, retrieves stuff then dispatches another action to hide Loader.

[EffectMethod]
public async Task GetStuff(ParmsAction<Stuff>  action, IDispatcher dispatcher)
{
	dispatcher.Dispatch(new ViewStateLoadingAction(true));

	try
    {
		var stuff= await _APIClient.GetStuff(action.param,);
        if (stuff == null)
        {
            //fail action
        }
        else if (stuff != null &&
                 stuff.Error is null)
        {
            //different state action
        }
        else
        {
          //fail action
        }
    }
    catch (HttpRequestException)
    {
       //fail action
    }
	var stopwatch = Stopwatch.StartNew();
        dispatcher.Dispatch(new ViewStateLoadingAction(true));
	stopwatch.Stop();
	Console.WriteLine($"ms: {stopwatch.ElapsedMilliseconds}"); //<-- why 2000-3000ms???
}

Why does the hide Loader action dispatch takes 2-3 seconds to complete?

[mrpmorris]

My guess is that your line just before stopwatch.Stop should be passing (false) not (true) - and that it is getting set to false by another api call later.

[alexgeorghiou]

That was a mistype, it is false in the source code. Would you say the delay is because of rerendering the UI?

…

On Tue, 4 Mar 2025 at 00:02, Peter Morris ***@***.***> wrote: My guess is that your line just before stopwatch.Stop should be passing (false) not (true) - and that it is getting set to false by another api call later. — Reply to this email directly, view it on GitHub <#534 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHFNUEXY7CHTN4BQEJZBKTL2STGODAVCNFSM6AAAAABYFME4L6VHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTEMZYGEZDKNA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[mrpmorris]

I'll need to look at code. Can you cut your app down to a very minimal reproduction?