"""
Wrapper for loading templates from "templates" directories in INSTALLED_APPS
packages.
"""
import os
import sys
from django.apps import apps
from django.conf import settings
from django.template.base import TemplateDoesNotExist
from django.template.loader import BaseLoader
from django.utils._os import safe_join
from django.utils import six
def calculate_app_template_dirs():
if six.PY2:
fs_encoding = sys.getfilesystemencoding() or sys.getdefaultencoding()
app_template_dirs = []
for app_config in apps.get_app_configs():
if not app_config.path:
continue
template_dir = os.path.join(app_config.path, 'templates')
if os.path.isdir(template_dir):
if six.PY2:
template_dir = template_dir.decode(fs_encoding)
app_template_dirs.append(template_dir)
return tuple(app_template_dirs)
# At compile time, cache the directories to search.
app_template_dirs = calculate_app_template_dirs()
class Loader(BaseLoader):
is_usable = True
def get_template_sources(self, template_name, template_dirs=None):
"""
Returns the absolute paths to "template_name", when appended to each
directory in "template_dirs". Any paths that don't lie inside one of the
template dirs are excluded from the result set, for security reasons.
"""
if not template_dirs:
template_dirs = app_template_dirs
for template_dir in template_dirs:
try:
yield safe_join(template_dir, template_name)
except UnicodeDecodeError:
# The template dir name was a bytestring that wasn't valid UTF-8.
raise
except ValueError:
# The joined path was located outside of template_dir.
pass
def load_template_source(self, template_name, template_dirs=None):
for filepath in self.get_template_sources(template_name, template_dirs):
try:
with open(filepath, 'rb') as fp:
return (fp.read().decode(settings.FILE_CHARSET), filepath)
except IOError:
pass
raise TemplateDoesNotExist(template_name)