admin.autodiscover() cannot locate admin inside an egg

[clint]

In Ticket #8126, a mechanism was added to admin.autodiscover() to be a little more intelligent about how it found and then tried to import admin.py files in applications.

In a project I'm working on now, we have the following structure (I've simplified this a little, obviously). /vendors/ is on my pythonpath.

myproject/
    settings.py
    myapp/
        admin.py
        models.py
    vendor/
       app1/
          models.py
          admin.py
       app2/
          models.py
          admin.py
       app3.egg/   <-- actual, zipped egg
          models.py
          admin.py
    urls.py

• When I syncdb, app3 is found and tables are made. I can import it in manage.py shell
• myapp above relates some models in app3 and when I go look at the admin pages for myapp it shows data from those tables.

So it sounds like most parts of Django are finding this application inside the egg just fine.

However:

• No admin pages for app3 show up in the admin site

From the above, I figured this was probably an issue in admin.autodiscover() not finding the admin.py. I looked in there and dugg into its code. The app path is discovered just fine by the code on line 25 of source:/django/trunk/django/contrib/admin/__init__.py

The apps that loop finds:

['/Users/phaedo/django_src/django/contrib/admin']
['/Users/phaedo/django_src/django/contrib/auth']
['/Users/phaedo/django_src/django/contrib/contenttypes']
['/Users/phaedo/django_src/django/contrib/sessions']
['/Users/phaedo/django_src/django/contrib/sites']
['/Users/phaedo/django_src/django/contrib/redirects']
['/Users/phaedo/src/ars-django-project/myproject/vendor/template_utils']
['/Users/phaedo/src/ars-django-project/myproject/vendor/debug_toolbar']
['/Users/phaedo/src/ars-django-project/myproject/vendor/dbtemplates']
['/Users/phaedo/src/ars-django-project/myproject/vendor/django_evolution']
['/Users/phaedo/src/ars-django-project/myproject/vendor/django_extensions']
['/Users/phaedo/src/ars-django-project/myproject/vendor/timezones']
['/Users/phaedo/src/ars-django-project/myproject/../myproject']
['/Users/phaedo/src/ars-django-project/myproject/vendor/app3-0.1-py2.5.egg/app3']   <--- there it is!
['/Users/phaedo/src/ars-django-project/myproject/myapp']
['/Users/phaedo/src/ars-django-project/myproject/vendor/signedcookies']

Then on line 34 it uses the method: imp.find_module() to see if an admin.py exists in each of those locations. When it looks into /Users/phaedo/src/ars-django-project/myproject/vendor/app3-0.1-py2.5.egg/app3 the method throws this exception:

ImportError: No frozen submodule named /Users/phaedo/src/ars-django-project/myproject/vendor/app3-0.1-py2.5.egg/app3.admin

and continues on to the next item in the list. BUT -- if I were to let that exception pass and move on to the actual import on line 40:

__import__("%s.admin" % app)

Then it imports just fine! So I can only guess at what's happening here.:

# imp.find_module has some sort of bug in it and can't find modules inside eggs
# If that's the case, perhaps Django should work around this?

It looks to me like everywhere else in Django is finding my application inside this egg and admin.autodiscover is doing something different.

My solution:

Cut out all the stuff happening on lines 34-37 and wrap the actual import an a try/except and catch the ImportError. Why do we need to find it before trying to import it? I've attached a patch to this effect. It seems to be like it would be backwards compatible and work around this strange "bug" in find_module.

[clint]

A patch to remove imp.find_module in admin.autodiscover

[clint]

After talking with Brian Rosner and Alex Gaynor in IRC just now, we need to do exception checking to make sure that errors inside admin.py aren't gobbled up. I have attached a new patch that attempts to import admin.py first, and then if that raised an ImportError, we check to see if the admin.py exists. If an ImportError was raised and we find that file to exist, we raise the error, otherwise continue.

[clint]

This patch allows errors in admin.py to bubble up

[Matt McDonald]

admin_autodiscover_impfix2.patch still does not let an ImportError within your egg'ed app's admin module to bubble up. I've taken a crack at a solution for this, and also supplied some additional comments to clarify things a bit.

See admin_autodiscover_impfix3.patch

[Karen Tracey]

(In [12989]) Fixed #9427: Allow for autodiscover to load admin modules from apps in eggs. Thanks clint and metzen.