[Fixed]-Dynamically loading django apps at runtime

by

4👍

✅

To answer my own question…

While I do not have a completely general solution to this problem, I do have one that is sufficient for the purposes of dynamically loading apps during testing.

The basic solution is simple, and I found it at a wee little bixly blog.

Continuing with my example above, if I was in a django shell and wanted to add and load some new apps that were added to my apps directory, I could do 

import os
from django.conf import settings
from django.db.models import loading
from django.core import management

APPS_DIR = '/path_to/apps/'

for item in os.listdir(APPS_DIR):
    if os.path.isdir(os.path.join(APPS_DIR, item)):
        app_name = 'apps.%s' % item
    if app_name not in settings.INSTALLED_APPS:
        settings.INSTALLED_APPS += (app_name, )

and then

loading.cache.loaded = False
management.call_command('syncdb', interactive=False)
👤mjandrews

15👍

Update for Django 1.8 on how to load an app that is not loaded yet

from collections import OrderedDict
from django.apps import apps
from django.conf import settings
from django.core import management

new_app_name = "my_new_app"

settings.INSTALLED_APPS += (new_app_name, )
# To load the new app let's reset app_configs, the dictionary
# with the configuration of loaded apps
apps.app_configs = OrderedDict()
# set ready to false so that populate will work 
apps.ready = False
# re-initialize them all; is there a way to add just one without reloading them all?
apps.populate(settings.INSTALLED_APPS)

# now I can generate the migrations for the new app
management.call_command('makemigrations', new_app_name, interactive=False)
# and migrate it
management.call_command('migrate', new_app_name, interactive=False)
👤Davide

6👍

With Django 2.2 this work for me

from collections import OrderedDict
from django.apps import apps
from django.conf import settings
from django.core import management

new_app_name = "my_new_app"

settings.INSTALLED_APPS += (new_app_name, )
apps.app_configs = OrderedDict()
apps.apps_ready = apps.models_ready = apps.loading = apps.ready = False
apps.clear_cache()
apps.populate(settings.INSTALLED_APPS)

management.call_command('makemigrations', new_app_name, interactive=False)

management.call_command('migrate', new_app_name, interactive=False)
👤Gersón Vizquel

3👍

It is possible to dynamically load and unload applications in tests in Django >= 1.7 (and also in the current 4.1) by a override_settings() decorator:

@override_settings(INSTALLED_APPS=[...])  # added or removed some apps
class MyTest(TestCase):
    # some tests with these apps
    def test_foo(self):
        pass

It has been possible since September 2014, not before the question.

Many other topics from the question are solved by django.apps also in Django >= 1.7. Generally: Dynamic configuration at startup is easy in the current Django. Dynamic loading and unloading after startup can’t be recommended in production, even that it could work eventually.

👤hynekcer

-1👍

Yes! Anything (or almost everything) in Python is possible. You should use os.walk() in order to get all folders, subfolders and files within your apps path in order to get all of your apps including the nested ones.

def get_installed_apps():
    from os import walk, chdir, getcwd
    previous_path = getcwd()
    master = []
    APPS_ROOT_PATH = '/my/project/apps/folder'
    chdir(APPS_ROOT_PATH)
    for root, directories, files in walk(top=getcwd(), topdown=False):
        for file in files:
            if 'apps.py' in file:
                app_path = f"{root.replace(BASE_DIR + '/', '').replace('/', '.')}.apps"
                print(app_path)
                master.append(app_path)
    chdir(previous_path)
    return master


print(get_installed_apps())
👤Jcc.Sanabria

Leave a comment