Best Practices with EntityManager - DevForce Community Forum

Originally posted by francois

Hi,
I'm busy evaluating DevForceEF to replace an existing in-house developed framework. Currently we have a client - server information system that is developed in a modular pattern. The client shell provides authentication / authorization services and a desktop. The client also currently support windows authentication and forms authentication.

The client have a plugin probe directory. If a plugin is found, it is loaded with dependency assemblies and the plugin injects the menus, views etc into the Desktop (very similar to CAB). These plugins can be mixed and matched as required. Each plugin assumes an already authenticated session provided by the client. Plugins can also extend other entities like CAB.

Implementing this with DevForceEF seems to be a bit more complex as I thought. The authentication / authorization of the client can be achieved by creating a very simple domain model and to use the login with custom login credentials. But how do I cater for the plugin design?

Each plugin is in a way it's own domain model (which could potentially have dependencies on other domain models for referential integrity).

Basic architecture guidelines would be great.

Thanks

Sorry for the delay, Francois. I ran this by Ward Bell, our VP of Product Development, who had the comments listed below.

It�s a sensible question but I don�t know enough about the plug-in authentication to suggest wisely.

Typically, I would do as he suggested for the opening gambit � login an EntityManager at the start. No unusual complexity there.

Then I would put an AuthenticationService and AuthorizationService in my IoC container. Subsequent plugins are serviced from these services.

I�m imagining that the plug-ins have their own domain models and, therefore, their own EntityManager instances. The question might be, �how do I login these Ems without actually going back to the user again for credentials?�

If this actually IS the question, the solution is easy. The plug-in can ask the AuthenticationService to �new� it�s own specialized EntityManager based on the originally logged in EM that is retained/referenced by the AuthenticationService.

I imagine a method such as

Service.CreateEntityManager<T>() where T : EntityManager, new()

The implementation is a one-liner sort of like:

return new T(HomeEntityManager); // HomeEntityManager provides access to the originally logged in EM

I don�t think I dare go further without more information about what seems to be the problem and desired outcome.

Perhaps Francois would like to contact us directly. [which you can do through support@ideablade.com]