AttributeBasedValidation

Attribute based validation -- reflection

        var masterModel = new Master
        {
            CantBeNull = new List<Child>
            {
                new Child
                {
                    NestedChildren = new List<Child>(),
                    Barcode = "12345678900",
                    Name = "Murat Ay"
                }
            },
            Child = new Child
            {
                NestedChildren = new List<Child>(),
                Barcode = "12345678900",
                Name = "Murat Ay"
            },
            Name = "Murat Ay",
            AppointmentDate = DateTime.Today.AddDays(-1),
            CanbeNull = null,
            EndDate = null,
            GsmNumber = "+90 588 888 88 88",
            IgnoreAbleProperty = null
        };

        var result = ValidationHelper.CheckModel(masterModel, true);
        Console.WriteLine(result.IsValid+" "+result.Error);
        Console.ReadLine();
        
public class Master
{
    [SmartString]
    public string Name { get; set; }

    [SmartString(regexPattern: @"5\d{9}\s*?$", minLength: 10, maxLength: 15, onlyDigit: true, changeProperty: true, subStringIndex: 10)]
    public string GsmNumber { get; set; }

    [SmartDateTime(notNullOrDefault: false, greaterOrEqualThanTomorrow: true)]
    public DateTime AppointmentDate { get; set; }

    [SmartDateTime(false, false, changeIfDefault: true, year: 2020, day: 31, month: 12)]
    public DateTime? EndDate { get; set; }

    public IList<Child> CanbeNull { get; set; }

    [SmartChildClass(true, minCollectionCount: 1)]
    public IList<Child> CantBeNull { get; set; }

    [SmartChildClass(isCollection: false)]
    public Child Child { get; set; }

    [SmartString(ignoreWhenPrompted: true)]
    public string IgnoreAbleProperty { get; set; }

}

public class Child
{
    [SmartString]
    public string Name { get; set; }

    [SmartString(minLength:10,maxLength:15)]
    public string Barcode { get; set; }

    [SmartChildClass(isCollection:true,minCollectionCount:0)]
    public IList<Child> NestedChildren { get; set; }

    [SmartChildClass(false)]
    public Child NestedChild { get; set; }
}