[Zope] Temporary Folder Content - Session Data

[Chris McDonough]

On Tue, 2003-05-27 at 11:53, Edward Pollard wrote:
> Sometimes I feel really bad writing to the list for help. It's when I 
> have very simple, very basic questions. I'm sure that the answer is 
> somewhere, but I've not been able to find it.

The likeliest place to find information about sessions in in the 2.6
edition of the Zope Book at
http://www.zope.org/Documentation/Books/ZopeBook/2_6Edition/Sessions.stx

> I'm having a thought that each of my Zope projects that uses sessions 
> should use individual session containers. I had some problems when one 
> of our student developers and I both shared the same variable names. 
> Quite hilarious.

Session data containers contain session data objects, each of which
should be unique for a particular browser (user).  It's true that each
developer will share the same session namespace for a given user, but
you don't need to limit yourself to storing string-valued key-value
pairs in the top-level namespace of the session data object.  For
example, instead of:

context.REQUEST.SESSION['avariable'] = 'avalue'

... you can do something like this:

my_app_namespace = context.REQUEST.SESSION.get('my_app', {})
my_app_namespace['avaraible'] = 'avalue'
context.REQUEST.SESSION.set('my_app', my_app_namespace)

In this case you are storing a dictionary named 'my_app' in the session
which (as long as no other developer uses 'my_app' as a top-level
session key) can be private to your application.

Read the section entitled "Mutable Data Stored Within Session Objects"
in the Zope Book sessions chapter to understand the 3rd line of the
above example.

> However, it seems to be conventional wisdom to store session data 
> containers in temporary folders, as the default session data container 
> is. This of course goes away on a restart.
> 
> Is there anyway to get them to stick, as the default session data 
> container does?

I'm afraid I don't understand what this has to do with namespace
conflicts... but you can create a session data container in your "main"
ZODB by selecting it from the Add... menu.  Then point your session data
manager at it.  The data will not go away then but it will be much more
prone to conflicts and thus perhaps performance problems.  This is also
detailed in the Zope Book chapter.

- C