Manual Custom Connection without having to leave the application

Using a DataSourceExtension you can connect to different environments/DBs at runtime. That's typically what you use if the user can select different environments/DBs from a drop down during login. In Cocktail you specify the DataSourceExtension through the ConnectionOptions. You can implement an IConnectionOptionsResolver to dynamically initialize the proper ConnectionOptions based on information that the user supplies during login. More on the DataSourceExtension can be found here:

Default, Fake and DesignTime are just three out-of-the-box preconfigured ConnectionOptions that cover the standard use cases. You can create as many of your own as you need. The easiest way is to clone an existing one if you only need to change one or two things. So, let's say I want to setup TempHire with a Development, Test and Production DB and I want to be able to specify at runtime, which of the three DBs I want to connect to. To keep it simple, I have hardcoded connection strings in my Web.config for each of the three environments:

1. How do I switch between two or more connections?
       start app
            login (in LoginView we have one ComboListBox with Connections)
                 -  Production
                 -  Development
                 x Test
            logout
            login
                 -  Production
                 x  Development
                 - Test
            logout
       exit  

2. How configure the authentication service with the same ConnectionOptions?

3. If we dont have the connections in app.config how we can to load them? (I mean with code)

DataSourceKeyResolver run only once, how do I switch?

Dear Marcel so far no so good,

my steps

a. public interface IUserSession   {
        string Name { get; set; }
    }

    [Export(typeof(IUserSession)), PartCreationPolicy(CreationPolicy.Shared)]
    public class UserSession : IUserSession    {
        public UserSession()        {   }
        public string Name { get; set; }
    }

b.public class EnvironmentResolver : IConnectionOptionsResolver  {     
        public ConnectionOptions GetConnectionOptions(string name)
        {
            IUserSession userSession = Composition.GetInstance<IUserSession>(CreationPolicy.Shared);
            if (name == userSession.Name)
                return ConnectionOptions.Default.WithDataSourceExtension(
                                userSession.Name.ToUpper()).WithName(userSession.Name);
            return null;
        }
    }
c. <connectionStrings>
      <add name="SecurityEntities" connectionString=...
  </connectionStrings>

d.class CustomDataSourceKeyResolver : IDataSourceKeyResolver {
    public GetKey(string keyName, string keyExtension, bool onServer) {
      if (!onServer) {return null;}
      if (keyName != "TempHireEntities" || string.IsNullOrEmpty(keyExtension)) { return null; }
      String connectionString = "";
      if (keyExtension == "PROD")   {
          connectionString = @"Data Source=.\SQLEXPRESS;Initial Catalog=TempHire_Production; ...
      }
      if (keyExtension == "TEST")    {
          connectionString = @"Data Source=.\SQLEXPRESS;Initial Catalog=TempHire_Test; ...
      }

      if(string.IsNullOrEmpty(connectionString ) { return null; }

      // Now build and return a "ClientEdmKey". 
      string name = string.IsNullOrEmpty(keyExtension) ? keyName : keyName + "_" + keyExtension;
      return new ClientEdmKey(name, connectionString, false, "FromResolver");
    }
  }

e.[Export]
    public IEntityManagerProvider<TempHireEntities> TempHireEntityManagerProvider    {
            get    {
                IUserSession userSession = Composition.GetInstance<IUserSession>(CreationPolicy.Shared);
                var provider = new EntityManagerProvider<TempHireEntities>()
                    .Configure(config => config.WithConnectionOptions(userSession.Name));
                return provider;
            }
        }

f. [ImportingConstructor]
   public LoginViewModel(IAuthenticationService authenticationService, IWindowManager windowManager,
                              [Import(AllowDefault = true)] IPreLoader preLoader, IUserSession userSession
           ....
            _userSession = userSession;
           ....

   _userSession.Name = filled from one new field named KeyName
    public string KeyName
        {
            get { return _keyName; }
            set
            {
                _keyName= value;
                _userSession.Name = value;
                NotifyOfPropertyChange(() => KeyName);
                NotifyOfPropertyChange(() => CanLogin);
            }
        }


g. before Login
    public IEnumerable<IResult> Login()  {
            _authenticationService. ??? There is no implementation to configure ConnectionOptions
            using (Busy.GetTicket()) ...

I am stuck

ps. If CustomDataSourceKeyResolver return null how can it manage from LoginViewModel

perfect
I noticed when  GetConnectionOptions take value is always "Default" and ConnectionOptions.Default.Name having the same value , always , that is correct?
because in this case we do not need to check out.

Also when we change the connection not fill the comboboxes at second database,
when change again the first database the comboboxes is correct


Edited by giotis - 04-Sep-2012 at 10:46pm

thank you very much
Also when we change the connection not fill the comboboxes at second database,
when change again the first database the comboboxes is correct why?

After selecting base (Prod) and connect all is well
When after changing the base(Test) the combobox(State) from Adresses are not filled,
If we go back to first base again all well