I want to store some things in a database, and am using the current session as a foreign key: from models.py
class Visited(models.Model):
session = models.ForeignKey(Session)
page = models.ForeignKey(Page)
times_visited = models.PositiveIntegerField()
ip_address = models.IPAddressField()
date_last_visited = models.DateTimeField()
def __unicode__(self):
return u'(%s, %s)' % (str(self.session.session_key), str(self.page.name))
To make a new entry for this model I'm using the following to get the current session (in views.py):
Session.objects.get(session_key=request.session.session_key)
However if it is the first time a user has visited the site, and thus do not have a cookie set yet, the code above will produce a DoesNotExist
error.
I know that even if there is now cookie set you can still set session objects. So I can think of a few hacks to make this work, such as:
But I would like a better solution I can live with. Are there any generally used or good solutions to this problem? Or am I even referencing sessions properly in my model?
Thank you for your help.
request.session
is a SessionStore object with a unique session_key.
The session_key is created as soon as the attribute is accessed. But the session object itself is only saved to the database after the view has been processed (in the process_response method of the session middleware) by calling the save method of the SessionStore object.
It's not really documented, but looking at the source code I guess you are supposed to create a new session object like this:
if not request.session.exists(request.session.session_key):
request.session.create()
You could also create custom session middleware, that makes sure your new session object is always available before any of your views tries to access it:
from django.conf import settings
from django.contrib.sessions.middleware import SessionMiddleware
class CustomSessionMiddleware(SessionMiddleware):
def process_request(self, request):
engine = import_module(settings.SESSION_ENGINE)
session_key = request.COOKIES.get(settings.SESSION_COOKIE_NAME, None)
request.session = engine.SessionStore(session_key)
if not request.session.exists(request.session.session_key):
request.session.create()
(Of course you must reference your new session middleware via the SESSION_ENGINE inside your settings.py
)
But be aware - this approach will generate a new session object for every request if the user's browser does not support cookies ...