Is it possible to show "Already Logged In" message if that user is logged on one of the machine. This thing is possible using database. But i had implemented sessions for login and logout,i think it isn't possible with sessions to show "Already Logged In".
Please suggest best way for this.
If they go to another computer? If you are using session[:something] - it is stored in the browser. For anything to be stored across a different browser, you have to use a database for state.
I think it is possible, but that being said, I don't like it. I take it you are concerned because you can't easily identify a user from the session data?
Make sure the User model is updated every time a user accesses the application by using a before_filter in the application controller.
During the login process, you can query "logged in" users by specifying a time limit that is the same as the session clean up time limit.
You can do something like this :
User.where("email = ? and updated_at >= ?",login_email,20.minutes.ago)
If you want to avoid concurrent logins for the same username. The best implementation can be achieved by adding a column to the users table that stores the ip address of the logged in user.
Otherwise you can change the session store mechanism to use either of:
in addition to the default CookieStore.
