FieldMaxLengthCondition.cs

using Sitecore.Data;
using Sitecore.Rules.Conditions;
using MyProject.Foundation.Validation.Rules.Contexts;


namespace MyProject.Foundation.Validation.Rules.Conditions
{
    public class FieldMaxLengthCondition<T> : IntegerComparisonCondition<T> where T : FieldValidatorsRuleContext
    {
        public string FieldId { get; set; }

        protected override bool Execute(T ruleContext)
        {
            if (ID.Parse(FieldId) != ruleContext.FieldId)
            {
                return false;
            }

            var length = string.IsNullOrWhiteSpace(ruleContext.FieldValue) ? 0 : ruleContext.FieldValue.Length;
            return BaseCompare(length);
        }


        public virtual bool BaseCompare(int value)
        {
            return Compare(value);
        }
    }
}