POCO - if POCO means pure .net class with only properties, where i can write validations in MVC

Question

Very new to POCO, find some google links but found many different stories. Some connected with Entity framework, lazy loading etc. Some says its a pure .det class. Atleast

Answer 1

Personally I like to make my POCOs partial classes with the basic properties needed to define that model and then put and validation logic in a separate class. e.g:

public partial class Wizard
{
    public string UserName { get; set; }
    public string EmailAddress { get; set; }
}

and then if I wanted to add validation to UserName:

public partial class Wizard
{
    [Required]
    [StringLength(20)]
    public string UserName { get; set; }
}

I know the complier just amalgamates the two classes anyway and you may be repeating properties but I think its the cleanest approach.

Another option is to use the MetadataType attribute.