How do I map entities with lazy-loaded properties (without causing them to load)?

Question

I'm using EF 4.1 and code-first in an MVC project, and AutoMapper to map entities to view models.

Prior to using code-first I was able to exclude navigation properties in order to prevent anything from being loaded that wasn't already. I'm using .Include() in my queries to include the references that I need in order to avoid additional database round-trips.

However, with code-first my entity only exposes an entity property (or ICollection if there are more than one). How can I know whether it has been loaded without triggering the load?

Assuming this can be done, is there a way to make this the default behavior for AutoMapper, so that I do not have to explicitly exclude members on every single entity?

Answer 1

You can check whether a reference or collection navigation property of an entity has been loaded by:

bool isLoaded1 = dbContext.Entry(entity).Reference(e => e.MyReferenceProperty)
                     .IsLoaded();
bool isLoaded2 = dbContext.Entry(entity).Collection(e => e.MyCollectionProperty)
                     .IsLoaded();