Keeping Django Views DRY

Question

I have some code that gets the current logged in user.

userID = request.session.get("_auth_user_id")
    if userID:
        loggedin_user = User.objects.get(pk=int(userID))
    else:
        loggedin_user = None

I want the username to show up on every page.

At the moment I am putting the code in every view and passing the user object to every template

return render_to_response('index.html', {loggedin_user})

This seems to go against django's D.R.Y ethic. How can I do this with repeating myself?

EDIT: Maybe User was a bad example.

What if I wanted to get a list of objects from the database,

items = Item.objects.all()

and list them on everypage.

Do I have to write that code and pass the list to the template in every view. Or can I write some code once that will make that list available to all templates?

Answer 1

You should use a custom template tag for something like that. You can fetch the data you need in the custom tag, and send it to the template. All you need to remember is to load the tag up in the template file you're going to use it in.

Answer 2

The user ID already exists within the session. As such, you do not need to keep passing it around.

{{ request.session._auth_user_id }}

That should work, but you need to add this in your TEMPLATE_CONTEXT_PROCESSORS in your settings file:

django.core.context_processors.request

In your render_to_response, you'd need to add the request as a parameter. For example:

 return render_to_response('test.html',{}, context_instance=RequestContext(request))

Answer 3

What about request.user?

if request.user.is_authenticated():
    name = request.user.username
else:
    name = "Anonymous"

Anyway, if it wasn't already available in django, I'd suggest you to write a Middleware class just like django.contrib.sessions.middleware.SessionMiddleware or django.contrib.auth.middleware.AuthenticationMiddleware. That class alters the request details before they are sent to a view.

If you needed it on a per-view basis, you could write a decorator to do that small bit, and @decorator the views you want.