Question

I have a class course like this:

public class course   
{
        public int CourseID { get; set; }
        public string Name { get; set; }   
        public Event Schedule {get; set;} //Event is coming from library Dday.iCal  
}     

Entity framework cannot correctly understand on how to save this property. ( I want to serialize it to string when saving, and keep it as event when worknig with it in my application.) So I have two methods, say, SerializeToString() and DeserializeFromString(). I want those methods to be applied only when saving to database.

What I came up with the following. Basically I’m trying to have a separate property as a string that will be saved in the database and Event will be ignored, but it doesn’t save anything to the database now. I’m not even sure if this is a good approach to do things, or there’s something better that can be done.:

 public class course   
    {
            public int CourseID { get; set; }
            public string Name { get; set; }  
            private Event _Schedule;
            [NotMapped]  
            public Event Schedule {  
            get
            {
                if (!String.IsNullOrEmpty(CourseSchedule))
                {
                    return DeserilizeFromString(CourseSchedule);
                }
                return new Event();
            }
            set
            {
                _schedule = value;
            }
            }  
            private string _courseSchedule;
            public string CourseSchedule { 
            get
            {
                return _courseSchedule;
            }
            private set
            {
                if (Schedule != null)
                {
                    _courseSchedule = SerializeToString(Schedule);
                }
                else
                {
                    _courseSchedule = null;
                }
            }   
 }

Answer 1

You should keep your models as minimalistic as possible, just the auto-properties and attributes. For more complex business logic it’s good to add another layer to your MVC pattern. This one is usually called Repository (hard to find a good tutorial on Repository Pattern though.. 🙁 )and comes between model and controller controller.

This also is very useful for performing unit tests. When properly implemented it allows you to do replace database dependency with collection during tests. This approach will require a bunch of additional work on the project.

One more approach (a simpler one) would be to add a ViewModel layer. Do it this way:

class MyModel
{
    public string Text { get; set; }
}

class MyViewModel : MyModel
{
    public new string Text
    {
        get { return base.Text; }
        set { base.Text =value.ToUpper(); }
    }
}

class Program
{
    static void Main(string[] args)
    {
        MyViewModel mvm = new MyViewModel();
        mvm.Text = "hello there";
        var s = ((MyModel) mvm).Text; // "HELLO THERE"
    }
}

In DataContext use MyModel in controller use MyViewModel.