Data Annotation Ranges of Dates

Question

Is it possible to use [Range] annotation for dates?

something like

[Range(typeof(DateTime), DateTime.MinValue.ToString(), DateTime.To         


        

Answer 1

I use this approach:

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter, AllowMultiple = false)]
internal sealed class DateRangeAttribute : ValidationAttribute
{
    public DateTime Minimum { get; }
    public DateTime Maximum { get; }

    public DateRangeAttribute(string minimum = null, string maximum = null, string format = null)
    {
        format = format ?? @"yyyy-MM-dd'T'HH:mm:ss.FFFK"; //iso8601

        Minimum = minimum == null ? DateTime.MinValue : DateTime.ParseExact(minimum, new[] { format }, CultureInfo.InvariantCulture, DateTimeStyles.None); //0 invariantculture
        Maximum = maximum == null ? DateTime.MaxValue : DateTime.ParseExact(maximum, new[] { format }, CultureInfo.InvariantCulture, DateTimeStyles.None); //0 invariantculture

        if (Minimum > Maximum)
            throw new InvalidOperationException($"Specified max-date '{maximum}' is less than the specified min-date '{minimum}'");
    }
    //0 the sole reason for employing this custom validator instead of the mere rangevalidator is that we wanted to apply invariantculture to the parsing instead of
    //  using currentculture like the range attribute does    this is immensely important in order for us to be able to dodge nasty hiccups in production environments

    public override bool IsValid(object value)
    {
        if (value == null) //0 null
            return true;

        var s = value as string;
        if (s != null && string.IsNullOrEmpty(s)) //0 null
            return true;

        var min = (IComparable)Minimum;
        var max = (IComparable)Maximum;
        return min.CompareTo(value) <= 0 && max.CompareTo(value) >= 0;
    }
    //0 null values should be handled with the required attribute

    public override string FormatErrorMessage(string name) => string.Format(CultureInfo.CurrentCulture, ErrorMessageString, name, Minimum, Maximum);
}

And use it like so:

[DateRange("2004-12-01", "2004-12-2", "yyyy-M-d")]
ErrorMessage = "Value for {0} must be between {1} and {2}")]