Question

I was wondering what the best way to use transations with the entity framework.

Say I have three repositories:

 Repo1(ObjectContext context)
 Repo2(ObjectContext context)
 Repo3(ObjectContext context)

and a service object that takes the three repositories:

 Service(Repo1 repo1,Repo2 repo2, Repo3 repo3)
 Serive.CreateNewObject <- calls repo1, repo2, repo3 to do stuff.

So when I create the service I create three repositories first and pass them down, each repositry takes a object context so my code looks something like this:

MyObjectContext context = new MyObjectContext();
Repo1 repo = new Repo1(context);
// etc

Now I have a controller class that is responsible for calling different services and compants of my application, showing the right forms etc. Now what I want to be able to do is wrap everything that happens in one of the controller methods in a transaction so that if some thing goes wrong I can rollback back.

The controller takes a few different Service objects, but doesn’t know anything about the object context.

My questions are:

1. Should the context be passed in to the service layer also.
2. How do I implement a transaction in the controller so that anything that happens in the service
   layers arn’t commited untill everything has passed.

Sorry if it’s a bit hard to understand..

Answer 1

Why doesn’t your controller know about the ObjectContext?

This is where I would put it. Check out – http://msdn.microsoft.com/en-us/magazine/dd882510.aspx – here the Command is what will commit/rollback the UnitOfWork(ObjectContext).

If you don’t want to have your Controller know exactly about the EF (good design) then you want to abstract your ObjectContext into an interface similar to the approach in the above link.