which is better multiple properties or behavior property

I have a set of contact infos that I will be displaying in an ASP.NET MVC page

They will either have an email address or information to contact

should I have this setup

public class Contact
{
    public int ID { get; set; }
    public string Name { get; set; }
    public string Email { get; set; }
    public string Explanation { get; set; }

}

where email address is shown when explanation is null

or

public class Contact
{
    public int ID { get; set; }
    public string Name { get;开发者_Go百科 set; }
    public string DisplayInfo { get; set; }
    public  int DisplayInfoType { get; set; }
}

where the display info type determines how I will display the info.

First approach: it's more expressive!

The domain model is more expressive in the first example; it speaks for itself what the data means.

That you need to have one of the two filled is a business rule which you don't need to express in the properties of your entities.

DisplayInfo or for that matter any similar display logic should be incorporated in the Views. The business logic is not responsible for what part of the domain has to be shown to the user on the view. This should be taken care at the view-level.

The first setup is better. It expresses what the fields do more effectively. It delays the execution of UI logic until the appropriate layer.

Also note that your Email may be empty as well as null. Additionally, you may get more use out of a field name such as ContactInstructions instead of Explanation (explanation of what?).