Immediate.Validation

Custom validation messages

A custom message can be provided to any validation using the Message property of a validation attribute. The message will be parsed for template parameters, which will be applied to the message before rendering to the validation result. The target property name is available as {PropertyName}, and its value via {PropertyValue}.

Other parameter values will be added using their property name suffixed with Value (for example, the GreaterThanAttribute uses a comparison parameter, so the value is available via ComparisonValue). If another property on the target class is referenced via nameof(Property), the name of that property will be available using the Name suffix (for example, ComparisonName for the comparison property).

        [Validate]
public partial record Query : IValidationTarget<Query>
{
	[GreaterThan(0, Message = "'{PropertyName}' must be greater than '{ComparisonValue}'")]
	public required int Id { get; init; }
}