UK Date format / Must be true (for T&C's) / Range "if"

GenericDataAnnotations.cs

namespace Helpers.Validators
{
  using System.ComponentModel.DataAnnotations;

	public class DateFormatAttribute : RegularExpressionAttribute
	{
		public DateFormatAttribute() : base(@"^((0[1-9])|([1-2][0-9])|3[0-1])\/((0[1-9])|(1[0-2]))\/[0-9]{4}$")
		{
			
		}

		public override bool IsValid(object value)
		{
			return true;
		}
	}
  
  
  public class EnforceTrueAttribute : ValidationAttribute
  {
		public override bool IsValid(object value)
		{
			return value != null
				&& value is bool
				&& (bool)value;
		}
	}
  
  public class RangeIfAttribute : RangeAttribute
  {
		public string DependentProperty { get; set; }
		public object TargetValue { get; set; }

		public RangeIfAttribute(int minimum, int maximum, string dependentProperty , object targetValue) : base(minimum, maximum)
		{
			DependentProperty = dependentProperty;
			TargetValue = targetValue;
		}

		protected override ValidationResult IsValid(object value, ValidationContext validationContext)
		{
			var containerType = validationContext.ObjectInstance.GetType();
			var field = containerType.GetProperty(DependentProperty);
			
			if (field != null)
			{				
				var dependentvalue = field.GetValue(validationContext.ObjectInstance, null);
			
				if ((dependentvalue == null && TargetValue == null) || (dependentvalue != null && dependentvalue.Equals(TargetValue)))
				{					
					if (!base.IsValid(value))
						return new ValidationResult(ErrorMessage, new[] { validationContext.MemberName });
				}
			}

			return ValidationResult.Success;
		}
	}
}