Calling an "asynchronous Javascript" from blazor interop

[vd3d]

Is your feature request related to a problem? Please describe.

Currently, we can call the standard Javascript function from C# by using JSRuntime.InvokeAsync.

But, it does not work if it is an asynchronous method. For example, a case I cannot solve right now.
I try to know if the browser geolocation is already granted or not, to do this I wish to call the "Permission API".

The problem is that this "Permission API" is async, so my Javascript looks like this:

window.isGeolocGranted = async () => {
  permission = await navigator.permissions.query({ name: 'geolocation' });
  return permission.state == 'granted';
}

After long research, I didn't find any elegant solution to this issue.

Describe the solution you'd like

Should we simply call this async method with the same JSRuntime.InvokeAsync ?

What if the permissions API is blocking, by example, on some device it requests 4/5 seconds to wake up the geolocation,
then it requests authorization to the user (again 10 or more possible seconds to wait, he can even drink a cafe before
answering 'yes')!

Related idea

In Xamarin, we have Xamarin.Essentials... having Blazor.Essentials will be amazing.
Why ? Because it can be very complex, mainly to test on all the browsers, all the different cases etc.
Also, having something common, will help to improve the robustness of such modules ;-)

Good luck!

Thanks for contacting us.
We're moving this issue to the Next sprint planning milestone for future evaluation / consideration. We will evaluate the request when we are planning the work for the next milestone. To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[captainsafia]

@vd3d We've added some documentation to cover this. You should be able to invoke asynchronous JavaScript methods using JS interop. Blazor will automatically unwrap the Promise for you so you can extract the value. The JS interop docs have more info.