DateTime (date and hour) validation with Data Annotation

Question

I have the following code:

        [DisplayName("58.Date and hour of birth")]
        [DataType(DataType.DateTime, ErrorMessage = "Please enter a valid date in the format dd/mm/yyyy hh:mm")]
        [Range(typeof(DateTime), "1/1/2011", "1/1/2016")]
        [RequiredToClose]
        public object V_58 { get; set; }

I want to force the inclusion of time (in format hh:mm) and not only the date. This code considers 1/1/2011 as valid when it shouldn't as it does not containt the hour , Any clue about how to express the correct format ? (dd/mm/yyyy hh:mm)

Answer 1

You could write your own ValidationAttribute and decorate the property with it. You override the IsValid method with your own logic.

public class MyAwesomeDateValidation : ValidationAttribute
{
    public override bool IsValid(object value)
    {
        DateTime dt;
        bool parsed = DateTime.TryParse((string)value, out dt);
        if(!parsed)
            return false;

        // eliminate other invalid values, etc
        // if contains valid hour for your business logic, etc

        return true;
    }
}

And finally, decorate your property:

[MyAwesomeDateValidation(ErrorMessage="You were born in another dimension")]
public object V_58 { get; set; }

Note: Be wary of multiple validation attributes on your properties, as the order in which they are evaluated is unable to be determined without more customization, and subsequently if validation logic overlaps, your error messages might not accurately describe what exactly you mean to be wrong with the property (yeah, that's a run-on sentence)