django-imagekit/imagekit/imagecache/backends/base.py
2012-09-06 09:11:18 -04:00

45 lines
1.1 KiB
Python

from ...utils import get_singleton
from django.core.exceptions import ImproperlyConfigured
def get_default_image_cache_backend():
"""
Get the default image cache backend.
"""
from django.conf import settings
return get_singleton(settings.IMAGEKIT_DEFAULT_IMAGE_CACHE_BACKEND,
'image cache backend')
class InvalidImageCacheBackendError(ImproperlyConfigured):
pass
class Simple(object):
"""
The most basic image cache backend. Files are considered valid if they
exist. To invalidate a file, it's deleted; to validate one, it's generated
immediately.
"""
def is_invalid(self, file):
if not getattr(file, '_file', None):
# No file on object. Have to check storage.
return not file.storage.exists(file.name)
return False
def validate(self, file):
"""
Generates a new image by running the processors on the source file.
"""
if self.is_invalid(file):
file.generate(save=True)
def invalidate(self, file):
file.delete(save=False)
def clear(self, file):
file.delete(save=False)