How to tell if any entities in context are dirty with .Net Entity Framework 4.0

Question

I want to be able to tell if there is any unsaved data in an entity framework context. I have figured out how to use the ObjectStateManager to check the states of existing entities, but there are two issues I have with this.

1. I would prefer a single function to call to see if any entities are unsaved instead of looping though all entities in the context.
2. I can't figure out how to detect entities I have added. This suggests to me that I do not fully understand how the entity context works. For example, if I have the ObjectSet myContext.Employees, and I add a new employee to this set (with .AddObject), I do not see the new entity when I look at the ObjectSet and I also don't see the .Count increase. However, when I do a context.SaveChanges(), my new entity is persisted...huh?

I have been unable to find an answer to this in my msdn searches, so I was hoping someone here would be able to clue me in.

Thanks in advance.

Answer 1

This article describes exactly what is needed to perform Change Tracking in the Entity Framework:

Identity Resolution, State Management, and Change Tracking (Entity Framework) - MSDN

Answer 2

var addedStateEntries = Context.ObjectStateManager.GetObjectStateEntries(EntityState.Added);

Answer 3

A simple way to get a reusable single method/property you could add a new method to your ObjectContext by creating a partial class and adding a property like this:

 public partial class MyEntityContext
{

    public bool IsContextDirty{
        get{
            var added = ObjectStateManager.GetObjectStateEntries(EntityState.Added);
            if(added != null && added.Count() > 0){
                return true;
            }
            var deleted = ObjectStateManager.GetObjectStateEntries(EntityState.Deleted);
            if (deleted != null && deleted.Count() > 0){
                return true;
            }
            var modified = ObjectStateManager.GetObjectStateEntries(EntityState.Modified);
            if(modified != null && modified.Count() > 0){
                return true;
            }
            return false;

        }
    }

Depending on what your looking for you could expose other properties to know if there are just deletes or modifications. This method could be simplified, but I wanted it to be clear what you would need to do.