[aspnetcore 10] minimal api validation - localization

[mkalinski93]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

hey folks,

Im trying desperately to use minimal api with the new validation support in .net 10.
The validation itself works good, but I came to notice that the data annotation validation is not localized whenever the request localization is changed. Default is english and the only way to come around seems to create custom data annotation attributes.

Expected Behavior

If the request locale is different than english, the failed validation should display the translated texts into the problem detail

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version

10.0.100

Anything else?

No response

[oroztocil]

We might want to tackle this together with #12158.

[oroztocil]

The design proposal for the localization support is in #65539.

[Digvijay]

I've been working on an experimental validation source generator called Sannr — a personal open-source project, not a competitor to the built-in validation.

Localization is supported today, including .resx resource files and format string placeholders, all checked at compile time:

[Display(Name = "User Age")]
[Range(18, 100, ErrorMessage = "The field {0} must be between {1} and {2}.")]
public int Age { get; set; }
// Output: "The field User Age must be between 18 and 100."

// Externalized resources
[Required(ErrorMessageResourceName = "RequiredField", ErrorMessageResourceType = typeof(Resources.Validation))]
public string? Name { get; set; }