django-avatar/avatar/utils.py
2022-08-09 21:17:24 +02:00

122 lines
3.6 KiB
Python

import hashlib
from django.contrib.auth import get_user_model
from django.core.cache import cache
from django.template.defaultfilters import slugify
from django.utils.encoding import force_bytes
from avatar.conf import settings
cached_funcs = set()
def get_username(user):
"""Return username of a User instance"""
if hasattr(user, "get_username"):
return user.get_username()
else:
return user.username
def get_user(username):
"""Return user from a username/ish identifier"""
return get_user_model().objects.get_by_natural_key(username)
def get_cache_key(user_or_username, size, prefix):
"""
Returns a cache key consisten of a username and image size.
"""
if isinstance(user_or_username, get_user_model()):
user_or_username = get_username(user_or_username)
key = "%s_%s_%s" % (prefix, user_or_username, size)
return "%s_%s" % (
slugify(key)[:100],
hashlib.md5(force_bytes(key)).hexdigest(),
)
def cache_set(key, value):
cache.set(key, value, settings.AVATAR_CACHE_TIMEOUT)
return value
def cache_result(default_size=settings.AVATAR_DEFAULT_SIZE):
"""
Decorator to cache the result of functions that take a ``user`` and a
``size`` value.
"""
if not settings.AVATAR_CACHE_ENABLED:
def decorator(func):
return func
return decorator
def decorator(func):
def cached_func(user, size=None, **kwargs):
prefix = func.__name__
cached_funcs.add(prefix)
key = get_cache_key(user, size or default_size, prefix=prefix)
result = cache.get(key)
if result is None:
result = func(user, size or default_size, **kwargs)
cache_set(key, result)
return result
return cached_func
return decorator
def invalidate_cache(user, size=None):
"""
Function to be called when saving or changing an user's avatars.
"""
sizes = set(settings.AVATAR_AUTO_GENERATE_SIZES)
if size is not None:
sizes.add(size)
for prefix in cached_funcs:
for size in sizes:
cache.delete(get_cache_key(user, size, prefix))
def get_default_avatar_url():
base_url = getattr(settings, "STATIC_URL", None)
if not base_url:
base_url = getattr(settings, "MEDIA_URL", "")
# Don't use base_url if the default url starts with http:// of https://
if settings.AVATAR_DEFAULT_URL.startswith(("http://", "https://")):
return settings.AVATAR_DEFAULT_URL
# We'll be nice and make sure there are no duplicated forward slashes
ends = base_url.endswith("/")
begins = settings.AVATAR_DEFAULT_URL.startswith("/")
if ends and begins:
base_url = base_url[:-1]
elif not ends and not begins:
return "%s/%s" % (base_url, settings.AVATAR_DEFAULT_URL)
return "%s%s" % (base_url, settings.AVATAR_DEFAULT_URL)
def get_primary_avatar(user, size=settings.AVATAR_DEFAULT_SIZE):
User = get_user_model()
if not isinstance(user, User):
try:
user = get_user(user)
except User.DoesNotExist:
return None
try:
# Order by -primary first; this means if a primary=True avatar exists
# it will be first, and then ordered by date uploaded, otherwise a
# primary=False avatar will be first. Exactly the fallback behavior we
# want.
avatar = user.avatar_set.order_by("-primary", "-date_uploaded")[0]
except IndexError:
avatar = None
if avatar:
if not avatar.thumbnail_exists(size):
avatar.create_thumbnail(size)
return avatar