WinRT, Code First - changing connection string on server side

Hi,

WinRT, Code First, DevForce 2012 7.2.

I am implementing quite common (I hope) SaaS scenario, where logged in user should connect to its own database (connection string for specific user is stored in central db). And here is my question - how to change connection string on the server side according to logged-in user? In other words, how to intercept each server side EntityManager call (query or save) to be able to read appropriate connection string from DB and then execute such calls (queries or save changes) with this new connection.

When I was working with 'old' Silverlight WCF application, I was able to achieve this by writing code in MyService.svc.cs class constructor and using HttpContext.Current.User.Identity to identify currently logged in user.

How to achieve this with DevForce?
I have no 'Entry point' in EntityManager class on server side where (in constructor or in OnInitialize() method) I could query central DB for new connection string and then change it for next DB operations.
I can't use HttpContext.Current.User.Identity too, until I'm using custom LoginManager.

I have tried to apply this description:

http://drc.ideablade.com/devforce-2012/bin/view/Documentation/persistent-connections

but there is no GetServerSessionInfo() method in SessionBundle.CurrentSessionBundle class (DevForce 7.2, Ultimate).

Are there any recommendation for achieving above scenario?
Thanks in advance.
       

Thank you, but it solves the problem only partially.
This solution assumes, that all connections will be stored in web.config, while in my case they will be stored in DB.

I know that connections in configuration can be changed dynamically, but still there is no place to do such change before executing each query and before saving each changes on server side.

Where is the best place (if any) to intercept each EntityManager communication with SQL server?

Hi

It works fine and it solves my scenario, thank you!

However in my case one user (some kind of supervisor) can have access to many databases (identical db schema, database can be chosen on client side, no relogin required). For that reason it would be very usefull if EntityManager had a method to change datasource without necessity of relogin - kind of myEntityManager.ChangeDataSource(string userName, string dataSourceName) with possibility of intercept this call on server side.

Thanks a lot for advices.

After several attempts I think, I am much more familiar with this mechanism.

I have noticed, that the only way to execute GetKey(...) method of RccDataSourceKeyResolver class (on server side) is to create a new instance of EntityManager (on client side) and then execute query, save or make login. GetKey() method is executed only once for one instance (logical).

The problem with this approach is a container (I'm using Unity on client side and my MyEntityManager is registered as an instance - singleton). When I have to instantiate new EntityManager each time when I want to change DB, I have to slightly break architecture and I have to expose my container as public static to be able to register new EntityManager instance somewhere inside AccountService (App.Container.RegisterInstance<MyEntityManager>(newMyEntityManager)). But anyway, problem solved.

I have only one short question regarding LoginManager - what is the main purpose of passing EntityManager to Login(...) method?