Question

I have a javascript application (ASP.net MVC 3 on the back end with SignalR) and i want to return only the fields that are needed (it must be dynamic).

I use the entity framework but i cant select only the specific columns because i need some fields for checking or something in the method that are no needed on the client side.

so, currently i make this:

    public void GetPerson(int personID)
    {
        // Some logic...

        // person is a entity from the entity framework (Person)
        dynamic p = new
        {
            ID = person.ID,
            FirstName = person.FirstName,
            LastName = person.LastName
        };

        Clients[Context.ConnectionId].loadPerson(p);
    }

But i’m not sure, if its a good practice (Performance etc.). Is there a better solution or can i still continue with the dynamic type?

Answer 1

Are you using the ExpandoObject?

Going by your example, maybe use just an anonymous type instead of a dynamic type.

 var p = new
        {
            ID = person.ID,
            FirstName = person.FirstName,
            LastName = person.LastName
        };

This will make sure that you still get compile-time checking. However, either should work. See this for more detail on anonymous vs dynamic.