[NET 11] feat: add support for async validation messages

[MarvinKlein1508]

🙋 Feature Request

It would be nice if we could add support for the new .NET 11 async validation capabilities directly into the FluentField component.

💁 Possible Solution

This could look like the demo from Daniel Roth which can be found here:

https://youtu.be/6c8fpShFjZE?si=2zn-jIIjpjbbUyJT&t=1513

🔦 Context

For example as been shown by Daniel we can have an interactive checking state build in into the component. The messages will then exchange once the validation is done.

[vnbaaij]

I'm not sure if that is something we need to include in the library.

If you look at Dan's sample code, you can see that the async part of this is arranged through adding a bespoke attribute (ie something the developer created) to a data model (also created by the developer).

Maybe we just need to have something like his BlazorFeatures/Components/AsyncFieldStatus.razor and hook that up to our FluentField?

[MarvinKlein1508]

Vincent Baaij (@vnbaaij) yes. I mean having the functionaltity from this AsyncFieldStatus.razor directly in FluentField. To indicate to the user that a validation is happening and then update the message accoridngly. Sure the developer can copy and paste this simple component but I think it would be nice to have within the library itself - because we already have a way to display a validation message in FluentField.

[dvoituron]

The current message handling is based on the .NET framework’s APIs. Wouldn’t it be better to see if .NET 11 adds this feature?
I’m not sure either whether it’s our role to include the code ‘officially’ in the library. Something to discuss.

[MarvinKlein1508]

Denis Voituron (@dvoituron) this shouldn't be a problem as this is fully managed by .NET 11. The part which I think we should add is this

@if (CurrentEditContext.IsValidationPending(field))
{
    <div class="field-status pending">@PendingMessage</div>
}
else if (CurrentEditContext.IsValidationFaulted(field))
{
    <div class="field-status faulted">@FaultedMessage</div>
}
else if (IsValidatedAvailable())
{
    <div class="field-status valid">@AvailableMessage</div>
}
else
{
    <ValidationMessage For="For" />
}

This are the new methods in .NET 11 to check the state of async validation. And since v5 is support this behaviour for the result of the validation message out of the box - it would be nice to have support for IsValidationPending and IsValidationFaulted out of the box.

[vnbaaij]

The code part for doing the async validation will probably not be that hard. The design is something that needs attention (maybe we can use a tiny spinner)
What I think will be more of a problem is how we can enable this for . NET 11 only.