When Entity Framework finally brought in support for Lazy Loading, there were still complaints. The lazy loading in EF4 is context based, not property based as defined by some of the other ORMs. (I’m not sure which ones or how many.)
I was thinking about this today and realized that EF does, in fact, support property level lazy loading.
There are three essential types of entities in EF4 –
- POCOs that lean on dynamic proxies at runtime
- POCOs that depend on EF’s snapshot notification
The POCOs that use dynamic proxies can do so only when every single property is marked virtual. Then they benefit from the same notification behavior at runtime as do EntityObjects and they benefit from lazy loading.
Simple POCOs that do not use dynamic proxies can still benefit from lazy loading. As long as the relationship property is marked virtual and additionally, properties that point to collections have to be a collection type that implements ICollection, the property will be loaded on demand (when the context’s lazy loading is enabled).
In this last case (the simple POCOs), you can pick and choose which of the relationship properties are able to lazy load. Then with the context set to LazyLoadingEnabled=true, lazy loading will occur, but only for the properties you have specified.
Now, I’m not sure how this compares to those other ORMs whose users criticized the context-level lazy loading, but it feels like it might be a lot closer then they realized. And I’m absolutely interested in finding out if I’m on the right track or completely off base (in which case I can only ask: “be gentle” 🙂 ).
Sign up for my newsletter so you don't miss my conference & Pluralsight course announcements!