Setting for prefix about django-cloudinary-storage

[klis87]

I see your use case now, and, as this will be backward compatible, we can include this in the package.

As I am quite busy recently, so I would really appreciate PR. Please include a test for this case.

[klis87]

Why do you need this? Cloudinary storage is just a custom Django storage implementation, which can be used for both static and media files. The default Django storages use MEDIA_URL and STATIC_URL settings, and in my opinion there is no need to introduce dedicated prefix settings for CLOUDINARY_STORAGE, as it would cause a following problems:

• unnecessary API pollution
• making CLOUDINARY_STORAGE less portable - the less work needs to be done when changing storages, the better

[seroy]

I have

DEFAULT_FILE_STORAGE = 'django.core.files.storage.FileSystemStorage'
MEDIA_URL = '/uploaded/'

but for some models/fields used cloudinary_storage.storage.MediaCloudinaryStorage and ran into side effect that all files uploaded at cloudinary via cloudinary_storage prefixed by '/uploaded/'

Code change is minimal, simple and 100% backward compatible. In app_settings.py add new line:

PREFIX = user_settings.get('PREFIX', settings.MEDIA_URL)

In storage.py change _get_prefix method to:

def _get_prefix(self):
   return app_settings.PREFIX

May be for most cloudinary-storage users it is not principal and they will never change that setting, but it make sense in my case.