Add context to every Django Admin page

Question

How do I add extra context to all admin webpages?

I use default Django Admin for my admin part of a site.

Here is an url entry for admin:

urlpatterns = [
    url(r'^admin/', admin.site.urls),
]

And my apps register their standard view models using:

admin.site.register(Tag, TagAdmin)

My problem, is that I want to display an extra field in admin template header bar and I have no idea how to add this extra context.

My first bet was adding it in url patterns like below:

urlpatterns = [
    url(r'^admin/', admin.site.urls, {'mycontext': '123'}),
]

But that gives an error:

TypeError at /admin/tickets/event/4/change/

change_view() got an unexpected keyword argument 'mycontext'

Can you give any suggestion? I really do not want to modify every AdminModel class I have to insert this context, as I need it on every admin page.

Thanks.

Answer 1

Another technique, more complex but allows different context per request (probably unavailable at OP time):

my_project/admin.py (create if missing)

from django.contrib import admin
from django.contrib.admin.apps import AdminConfig


class MyAdminConfig(AdminConfig):
    default_site = 'my_project.admin.MyAdminSite'


class MyAdminSite(admin.AdminSite):
    def each_context(self, request):
        context = super().each_context(request)
        context.update({
            "whatever", "this is",
            "just a": "dict",
        })
        return context

settings.py

INSTALLED_APPS = [
    ...
    'my_project.admin.MyAdminConfig',  # replaces 'django.contrib.admin'
    ...

The replace / extend admin class code is taken from the official docs except this is all in one file.