Using [ImportingConstructor] to import calling object into constructor parameter using MEF

Question

I am in the process of converting some of my code to MEF from a proprietary system that sort of does the same thing as MEF, and I have a question about how I would accomplish the following problem that I recently ran into.

I have a typical entity object that looks something like this:

public class Account {

    [Import]
    public IAccountServerService { get; set; }
}

And a service object that needs to be imported in to the above entity object:

public class AccountServerService : IAccountServerService {

    [ImportingConstructor]
    public AccountServerService (Account account) { ... }
}

To put this into words I need the account parameter passed into the AccountServerService constructor instance to be the object of the calling Account object. So that it act like this:

public class Account {

    public IAccountServerService { get { return new AccountServerService (this); } }
}

Please let me know if this scenario is possible or if I have to refactor my service interface in this instance.

Answer 1

So MEF does support circular dependencies but they must both be property imports, neither of them can be constructor imports. So the following should work from a MEF standpoint, of course I'm not sure if this approach is blocked by some other constraint you have.

public class AccountServerService : IAccountServerService {
    [Import]
    public Account Account { get; set; }

    public AccountServerService () { ... }
}

public class Account {
    [Import]
    public IAccountServerService { get; set; }
}