Is there a way to resolve ValidationAttribute.IsValid() asynchronously?

Question

Is there a way to resolve ValidationAttribute.IsValid() asynchronously?

David Thielen 3,211

Hi all; I have an IsValid() call that checks in registration to insure the user's email is not already in our user DB. To do so I need to query the database which is an async call. Is there any way to return a Task from IsValid or some other way return immediately and then later, when the query completes, then tell Blazor if the value is valid? thanks - dave

Farid Uddin Kiron MSFT 456 Reputation points Microsoft External Staff

2023-04-17T08:59:57.22+00:00

Actually, blazor doesn't support async operation on validation. However, you could have look few work around here if that fits your requirement. In addition, you can also check this document.
David Thielen 3,211 Reputation points

2023-04-17T14:50:05.31+00:00

Farid - that 2nd link you provided is exactly what I need. And hopefully, someday, they'll add an IsValidAsync(). But until then bind-after provides a decent approach. And I'll add one thing to that article - use CustomValidation to display the error. Much easier than hacking into ValidationMessageStore (see details here).
Farid Uddin Kiron MSFT 456 Reputation points Microsoft External Staff

2023-04-18T01:35:43.1533333+00:00

Thanks for your response and glad to hear that shared resource helped you.

Your answer

Farid Uddin Kiron MSFT 456 Reputation points Microsoft External Staff

2023-04-17T08:59:57.22+00:00

Actually, blazor doesn't support async operation on validation. However, you could have look few work around here if that fits your requirement. In addition, you can also check this document.
David Thielen 3,211 Reputation points

2023-04-17T14:50:05.31+00:00

Farid - that 2nd link you provided is exactly what I need. And hopefully, someday, they'll add an IsValidAsync(). But until then bind-after provides a decent approach. And I'll add one thing to that article - use CustomValidation to display the error. Much easier than hacking into ValidationMessageStore (see details here).
Farid Uddin Kiron MSFT 456 Reputation points Microsoft External Staff

2023-04-18T01:35:43.1533333+00:00

Thanks for your response and glad to hear that shared resource helped you.

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Is there a way to resolve ValidationAttribute.IsValid() asynchronously?

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