[imp] $imp vs. $_SESSION['imp']

[Chuck Hagenbuch]

Quoting Otto Stolz <Otto.Stolz at uni-konstanz.de>:

> - Is there any difference between $imp and $_SESSION['imp']?

Use $_SESSION['imp']. $imp is a not-entirely-reliable reference to  
$_SESSION['imp'].

> - Are they preserved over a user session, and are they
>   kept apart across user sessions?

They _are_ session data.

> - Can I write in my own component, say $imp['knu'],
>   and will this component be preserved over a user session?

Yes.

> - Or should I rather use $imp['cache']['knu']?

I'm not sure why 'cache'.

>   Or perhaps $_SESSION['imp']$imp['cache']['knu']?

I don't understand what that would be.

> - When and how are these arrays set, during login;
>   which custom hooks can rely on them, and which can't?

They're set by IMP_Session::createSession(). Hooks called after that  
function is called can rely on them, others can't. Off-hand I can't  
tell you which those are.

-chuck

-- 
"we are plastered to the windshield of the bus that is time." - Chris