Move the IValidationRule<T, TProperty>.SetDisplayName(string) method to the IValidationRule interface.

[GillesTourreau]

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

When creating an inherited class from the AbstractValidator<T> it is not possible when overriding the OnRuleAdded() method, to change the display name of the property.

protected override void OnRuleAdded(IValidationRule<T> rule)
{
    // Unable to change the display name using rule.SetDisplayName()
}

It is also not possible to cast the rule into the IValidationRule<T, out TProperty> because the OnRuleAdded() is called for each property to validate.

Describe the solution you'd like

It will be great to move IValidationRule<T, TProperty>.SetDisplayName(string) method to the IValidationRule interface.

protected override void OnRuleAdded(IValidationRule<T> rule)
{
    rule.SetDisplayName("My display name property");
}

Describe alternatives you've considered

We can use reflection currently for this work around:

protected override void OnRuleAdded(IValidationRule<T> rule)
{
    var setDisplayNameMethod = rule.GetType().GetMethod("SetDisplayName", new[] { typeof(string) })!;
    setDisplayNameMethod.Invoke(rule, new object[] { "My display name property" });
}

Additional Context

No response

[JeremySkinner]

Thanks for the suggestion. Seems like a reasonable idea, although it would need to wait until 12.0 as this is a breaking change.