Make sure user is logged in then show pages EXCEPT for login page.

[eluser]Pert[/eluser]
[quote author="behnampmdg3" date="1370160864"]
I can add a "session check and redirect to login" in _constructor of all controlers but I prefer add it in 1 place and so I wont have to change everything.
[/quote]

You can create a user model and autoload it, then check login state in model __construct method. When not logged in and not on login page, redirect to login page.