django-imagekit/imagekit/utils.py
Matthew Tretter 90ae9e8339 Fix get_nonabstract_descendants
Previously, function was only returning the first non-abstract
descendant. (It should also return concrete descendants of concrete
descendants, which it now does.)

Also, converted to generator.
2013-02-10 15:58:22 -05:00

141 lines
4.2 KiB
Python

import logging
from tempfile import NamedTemporaryFile
from django.core.exceptions import ImproperlyConfigured
from django.core.files import File
from django.db.models.loading import cache
from django.utils.importlib import import_module
from pilkit.utils import *
def get_spec_files(instance):
try:
return instance._ik.spec_files
except AttributeError:
return []
def _get_models(apps):
models = []
for app_label in apps or []:
app = cache.get_app(app_label)
models += [m for m in cache.get_models(app)]
return models
def get_nonabstract_descendants(model):
""" Returns all non-abstract descendants of the model. """
if not model._meta.abstract:
yield model
for s in model.__subclasses__():
for m in get_nonabstract_descendants(s):
yield m
def get_by_qname(path, desc):
try:
dot = path.rindex('.')
except ValueError:
raise ImproperlyConfigured("%s isn't a %s module." % (path, desc))
module, objname = path[:dot], path[dot + 1:]
try:
mod = import_module(module)
except ImportError, e:
raise ImproperlyConfigured('Error importing %s module %s: "%s"' %
(desc, module, e))
try:
obj = getattr(mod, objname)
return obj
except AttributeError:
raise ImproperlyConfigured('%s module "%s" does not define "%s"'
% (desc[0].upper() + desc[1:], module, objname))
_singletons = {}
def get_singleton(class_path, desc):
global _singletons
cls = get_by_qname(class_path, desc)
instance = _singletons.get(cls)
if not instance:
instance = _singletons[cls] = cls()
return instance
def autodiscover():
"""
Auto-discover INSTALLED_APPS imagegenerators.py modules and fail silently
when not present. This forces an import on them to register any admin bits
they may want.
Copied from django.contrib.admin
"""
from django.conf import settings
from django.utils.importlib import import_module
from django.utils.module_loading import module_has_submodule
for app in settings.INSTALLED_APPS:
mod = import_module(app)
# Attempt to import the app's admin module.
try:
import_module('%s.imagegenerators' % app)
except:
# Decide whether to bubble up this error. If the app just
# doesn't have an imagegenerators module, we can ignore the error
# attempting to import it, otherwise we want it to bubble up.
if module_has_submodule(mod, 'imagegenerators'):
raise
def get_logger(logger_name='imagekit', add_null_handler=True):
logger = logging.getLogger(logger_name)
if add_null_handler:
logger.addHandler(logging.NullHandler())
return logger
def get_field_info(field_file):
"""
A utility for easily extracting information about the host model from a
Django FileField (or subclass). This is especially useful for when you want
to alter processors based on a property of the source model. For example::
class MySpec(ImageSpec):
def __init__(self, source):
instance, attname = get_field_info(source)
self.processors = [SmartResize(instance.thumbnail_width,
instance.thumbnail_height)]
"""
return (
getattr(field_file, 'instance', None),
getattr(getattr(field_file, 'field', None), 'attname', None),
)
def generate(generator):
"""
Calls the ``generate()`` method of a generator instance, and then wraps the
result in a Django File object so Django knows how to save it.
"""
content = generator.generate()
# If the file doesn't have a name, Django will raise an Exception while
# trying to save it, so we create a named temporary file.
if not getattr(content, 'name', None):
f = NamedTemporaryFile()
f.write(content.read())
f.seek(0)
content = f
return File(content)
def call_strategy_method(generator, method_name, *args, **kwargs):
strategy = getattr(generator, 'cachefile_strategy', None)
fn = getattr(strategy, method_name, None)
if fn is not None:
fn(*args, **kwargs)