= Problem =

You wish to store server-side information about client agents; 
this information should follow around users as they browse through the application.

= Solution =

Enable sessions by using the `SessionPublisher` class instead of the regular `Publisher`.  
In your top-level script, simply do:

{{{
from quixote.publish import SessionPublisher
...
publisher = SessionPublisher()
}}}


= Discussion =

`SessionPublisher` uses two auxiliary classes:

 * `SessionManager` is a singleton (meaning there's only one instance of it) that's responsible for creating new Sessions and storing them.
 * `Session` contains information about the session.  Most of its attributes are of little interest    to a web application programmer; the single exception is the `.user` attribute, which you can use     to record user information.  The data type for `.user` isn't defined, so you can set it to a string,     an instance of your own User class, or whatever you wish.  The [[http://www.mems-exchange.org/software/dulcinea/|Dulcinea package]]    includes a `User` class that you may want to look at.

The standard version of `SessionManager` stores sessions in a Python dictionary.  This means that you must 
be invoking Quixote through some mechanism that uses long-lived processes; this rules out CGI, 
but any of FastCGI/SCGI/mod_python will work fine.   If you have multiple processes, though, sessions
will not be shared between them.  For such situations you would have to write a `SessionManager` subclass that stored sessions in 
a relational database or disk file.


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CategoryCookbook