+
−"""
+
−Wrapper for loading templates from "template" directories in INSTALLED_APPS
+
−packages.
+
−"""
+
−
+
−import os
+
−
+
−from django.conf import settings
+
−from django.core.exceptions import ImproperlyConfigured
+
−from django.template import TemplateDoesNotExist
+
−from django.utils._os import safe_join
+
−
+
−# At compile time, cache the directories to search.
+
−app_template_dirs = []
+
−for app in settings.INSTALLED_APPS:
+
−    i = app.rfind('.')
+
−    if i == -1:
+
−        m, a = app, None
+
−    else:
+
−        m, a = app[:i], app[i+1:]
+
−    try:
+
−        if a is None:
+
−            mod = __import__(m, {}, {}, [])
+
−        else:
+
−            mod = getattr(__import__(m, {}, {}, [a]), a)
+
−    except ImportError, e:
+
−        raise ImproperlyConfigured, 'ImportError %s: %s' % (app, e.args[0])
+
−    template_dir = os.path.join(os.path.dirname(mod.__file__), 'templates')
+
−    if os.path.isdir(template_dir):
+
−        app_template_dirs.append(template_dir)
+
−
+
−# It won't change, so convert it to a tuple to save memory.
+
−app_template_dirs = tuple(app_template_dirs)
+
−
+
−def get_template_sources(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(template_name, template_dirs=None):
+
−    for filepath in get_template_sources(template_name, template_dirs):
+
−        try:
+
−            return (open(filepath).read().decode(settings.FILE_CHARSET), filepath)
+
−        except IOError:
+
−            pass
+
−    raise TemplateDoesNotExist, template_name
+
−load_template_source.is_usable = True