Support for new .Net 6.0 DateOnly and TimeOnly types for binding Date and Time pickers

[bignorm64]

.Net 6.0 introduces new types DateOnly and TimeOnly (at last) and it would be very useful if the Date and Time picker components (or variations of them) supported binding to these types as appropriate.

[snow-jallen]

Any news on this one?

[ScarletKuro]

You can use converter to convert between DateTime and DateOnly \ TimeOnly.
Supporting this would either require duplicating the MudDatePicker and MudTimePicker component, or as alternative it would require to duplicate all the DateTime properties and callbacks with the corresponding *Only type.
I don't think either of this is a good design and the benefit is really questionable when the converter just does the job.

Maybe if C# adds Discriminated Unions then we can get back to it.

[sveins12]

I think that the most logic approach would be if date picker supported only DateOnly, and the time picker only TimeOnly. That's what they really are.

[ArieGato]

Would it be an idea to add a code analyzer to check for valid types for the generic date picker?

[ArieGato]

@henon when are we going to remove .net 7 support? Official support end date is May 14, 2024. I want to use the TimeProvider introduced in .net 8 in the DatePicker to improve unit testability.

[henon]

It won't be so soon as that, we discussed it already on the team. We don't want to force everybody to upgrade to .net8 ASAP.

[ArieGato]

Understood, can I use ISystemClock instead?

[henon]

I guess so. We can switch to TimeProvider once we drop net7

[ArieGato]

@henon I'm running into some issues with auto generated test code.

1. In the ApiDocsTest generated code a class T is used. But T doesn't match the generic constraint for the MudDatePicker where T : struct. When I change the class to struct then MudSlider_API_Test fails.

System.InvalidCastException : Unable to cast object of type 'MudBlazor.UnitTests.T' to type 'System.IConvertible'.

2. AllMudComponents_ShouldForwardUserAttributes uses string as default generic parameter for generic components. Also not matching the constraint.

Who can point me in the right direction how I can solve these issues? I could use reflection to determine any generic parameter constraints, but I would like to know if that is the right course of action.

[ScarletKuro]

This https://github.com/MudBlazor/MudBlazor/blob/dev/src/MudBlazor.Docs.Compiler/T.cs could be the culprit
as the doc compiler will use this T for the typeof(MudAutocomplete<T>) etc, never liked this part, as the CreateParameter should use typeof(MudAutocomplete<>) and use MakeGenericType to construct it.

[ScarletKuro]

Oh I didn't read attentively, you found the actual problem, but answering on your question

I could use reflection to determine any generic parameter constraints, but I would like to know if that is the right course of action.

That's the only correct and available option. But please, create a separate PR for this, if you find a solution and tag me.

[ArieGato]

@ScarletKuro I see that you've modified class T which I thought I was supposed to remove.

The resulting generated code should look something like this, right:

[Test]
public void MudDataGrid_API_Test()
{
    ctx.Services.AddSingleton<NavigationManager>(new MockNavigationManager("https://localhost:2112/", "https://localhost:2112/api/MudDataGrid<T>"));
    ctx.RenderComponent<DocsApi>(ComponentParameter.CreateParameter("Type", typeof(MudDataGrid<>).MakeGenericType(typeof(string))));
}

For the DatePicker I still need to add an exception because it is impossible to determine which class to use to make the Picker generic.

[ScarletKuro]

@ScarletKuro I see that you've modified class T which I thought I was supposed to remove.

We decided it's the easiest solution for the this change #8745 (comment) I had no time to overhaul how unit tests & docs work.
But @henon said that in future we should solve it for good #8745 (comment)

If you have a solution to remove it, go for it, but I would probably make it as separate PR not part of the datapicker