pluto/core/util/django_settings_export.py

70 lines
2.2 KiB
Python

"""
Export Django settings to templates
https://github.com/jakubroztocil/django-settings-export
"""
from django.conf import settings as django_settings
from django.core.exceptions import ImproperlyConfigured
__version__ = "1.2.1"
VARIABLE_NAME = getattr(django_settings, "SETTINGS_EXPORT_VARIABLE_NAME", "settings")
class SettingsExportError(ImproperlyConfigured):
"""Base error indicating misconfiguration."""
class UndefinedSettingError(SettingsExportError):
"""An undefined setting name included in SETTINGS_EXPORT."""
class UnexportedSettingError(SettingsExportError):
"""An unexported setting has been accessed from a template."""
def settings_export(request):
"""
The template context processor that adds settings defined in
`SETTINGS_EXPORT` to the context. If SETTINGS_EXPORT_VARIABLE_NAME is not
set, the context variable will be `settings`.
"""
variable_name = getattr(
django_settings, "SETTINGS_EXPORT_VARIABLE_NAME", "settings"
)
return {variable_name: _get_exported_settings()}
class ExportedSettings(dict):
def __getitem__(self, item):
"""Fail loudly if accessing a setting that is not exported."""
try:
return super(ExportedSettings, self).__getitem__(item)
except KeyError:
if hasattr(self, item):
# Let the KeyError propagate so that Django templates
# can access the existing attribute (e.g. `items()`).
raise
raise UnexportedSettingError(
"The `{key}` setting key is not accessible"
' from templates: add "{key}" to'
" `settings.SETTINGS_EXPORT` to change that.".format(key=item)
)
def _get_exported_settings():
exported_settings = ExportedSettings()
for key in getattr(django_settings, "SETTINGS_EXPORT", []):
try:
value = getattr(django_settings, key)
except AttributeError:
raise UndefinedSettingError(
'"settings.%s" is included in settings.SETTINGS_EXPORT '
"but it does not exist. " % key
)
exported_settings[key] = value
return exported_settings