using System;
using System.Collections;
using System.ComponentModel.DataAnnotations;

namespace EPAServeur.Attributes
{
    /// <summary>
    /// Specifies that a collection of a specified type must have at least one element.
    /// </summary>
    [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter, AllowMultiple = false)]
    public sealed class CannotBeEmptyAttribute : RequiredAttribute
    {
        public override bool IsValid(object value)
        {
            var list = value as IEnumerable;
            return list != null && list.GetEnumerator().MoveNext();
        }
    }
}