I get this traceback:
Traceback (most recent call last):
File "./manage.py", line 38, in <module>
execute_from_command_line(sys.argv)
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
utility.execute()
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/core/management/__init__.py", line 354, in execute
django.setup()
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/__init__.py", line 21, in setup
apps.populate(settings.INSTALLED_APPS)
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/apps/registry.py", line 108, in populate
app_config.import_models(all_models)
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/apps/config.py", line 197, in import_models
self.models_module = import_module(models_module_name)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
__import__(name)
File "/Users/mgregory/Documents/cm_central/cmh_server/models.py", line 88, in <module>
class VersionSerializer(serializers.ModelSerializer):
File "/Users/mgregory/Documents/cm_central/cmh_server/models.py", line 89, in VersionSerializer
brzs= BrzSerializer(many=True)
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/rest_framework/serializers.py", line 198, in __init__
self.fields = self.get_fields()
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/rest_framework/serializers.py", line 234, in get_fields
default_fields = self.get_default_fields()
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/rest_framework/serializers.py", line 732, in get_default_fields
reverse_rels = opts.get_all_related_objects()
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/db/models/options.py", line 498, in get_all_related_objects
include_proxy_eq=include_proxy_eq)]
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/db/models/options.py", line 510, in get_all_related_objects_with_model
self._fill_related_objects_cache()
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/db/models/options.py", line 533, in _fill_related_objects_cache
for klass in self.apps.get_models(include_auto_created=True):
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/utils/lru_cache.py", line 101, in wrapper
result = user_function(*args, **kwds)
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/apps/registry.py", line 168, in get_models
self.check_models_ready()
File "/Users/mgregory/Documents/virtualenvs/cm_central/lib/python2.7/site-packages/django/apps/registry.py", line 131, in check_models_ready
raise AppRegistryNotReady("Models aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet.
from this code (models.py):
# Serializers for transmitting CMx install information over HTTP
class BrzSerializer(serializers.ModelSerializer):
class Meta:
model = Brz
fields=('filename',)
class VersionSerializer(serializers.ModelSerializer):
brzs= BrzSerializer(many=True)
class Meta:
model = Version
fields=('name', 'for_mac', 'for_windows', 'brzs')
It sounds like it's telling me "your VersionSerializer can't have a BrzSerializer, because you haven't registered that yet".
I've looked at other SO questions relating to AppRegisteryNotReady, but didn't find one that matches this symptom. Surely I have to be able to define a chain of dependent models like this?
It turns out that having the declaration of the serializers inside models.py is causing that application to be used before the app registry has finished being loaded.
models.py is actually the wrong place to declare these serializers (though I'm 99% certain I did it that way based on an example of how to use them).
The fix is to move the declaration of the serializers out into their own file (which makes sense, because they have nothing to do with the database schema, which models.py is defining), and import that from the view. By the time the view gets going, the app registry is ready.