Set script prefix in django.setup() to allow its usage outside of requests

[Dougal Sutherland]

The script prefix for django.core.urlresolvers doesn't get set to anything when being called through manage.py, because of course it doesn't know what that value should be. This is a problem if you're rendering views (or otherwise reversing urls) from a manage.py command (as one of my sites does to send emails).

This is solvable by calling set_script_prefix from settings.py, but that feels kind of dirty since it's then about to be rewritten in the WSGI handler.

I don't know what a good solution to this would be. Perhaps it would be nice to be able to set a global default script path somewhere that would then get incorporated into the default values of things like LOGIN_URL.

Maybe just a note in the documentation would be good. It took me a while to figure out, because I haven't been able to find anything else about this online. (I guess that non-/ script paths are uncommon and reversing urls from manage.py is also uncommon, so both together are very uncommon.)

[Aymeric Augustin]

Based on code inspection, I confirm that this bug exists.

Possible fix: django.core.management.setup_environ could do something along the lines of:

from django.conf import settings
from django.core.management.base import set_script_prefix
from django.utils.encoding import force_unicode

set_script_prefix(u'/' if settings.FORCE_SCRIPT_NAME is None else force_unicode(settings.FORCE_SCRIPT_NAME))

[Akos Ladanyi]

If it is not possible to figure out the value of script_prefix in all cases (like in manage.py) why not just store its value in a settings variable? Then reverse could just prepend this value to all paths deduced from urlconf.

[julen]

Would it make sense to call set_script_prefix() in ManagementUtility's execute() method, ​once settings have been configured?

[Tim Graham]

django.setup() seems to be a natural place for it.

[julen]

I thought so initially, but this issue is limited to management commands, that's why I wonder about ManagementUtility.execute(). Once the right location for this is confirmed, the fix should be trivial.

[Tim Graham]

I imagine it would also affect standalone scripts that invoke django.setup() but don't use ManagementUtility.

[Claude Paroz <claude@…>]

In 7d81ee6e:

Fixed #16734 -- Set script prefix even outside of requests

Thanks Tim Graham for the review.