Question

I want to be able to use extra variables on a custom 404 template.

#404.html
{{ extra_var }}

I have already tried:

#urls.py
from myproject.myapp import views
handler404 = views.handler404

#views.py
from django.template import RequestContext, loader
from django import http
def handler404(request):
    extra_var = 'my_extra_var'
    t = loader.get_template('404.html')
    return http.HttpResponseNotFound(t.render(RequestContext(request, 
      {'request_path': request.path, 'extra_var': extra_var, })))

However, it doesn’t seem to work: I can only access to request_path.

Answer 1

The fact that you can access request_path but not extra_var suggests to me your view is not being called properly, since request_path is passed automatically to the 404.html template, per the documentation:

If you don’t define your own 404 view
— and simply use the default, which is recommended — you still have one
obligation: you must create a 404.html
template in the root of your template
directory. The default 404 view will
use that template for all 404 errors.
The default 404 view will pass one
variable to the template:
request_path, which is the URL that
resulted in the 404.

I think you need to give handler404 a string, rather than a module, like this:

handler404 = 'myproject.myapp.views.handler404'