from typing import Any, Dict, List, Optional from django.apps import apps from openslides.utils import logging logger = logging.getLogger(__name__) class UserBackendException(Exception): pass class BaseUserBackend: """ Base user backend providing methods to overwrite and provides a representation for clients. The backendname must be unique. """ @property def name(self) -> str: raise NotImplementedError("Each Backend must provie a name") def get_disallowed_update_keys(self) -> List[str]: raise NotImplementedError("Each Backend must provie a name") def for_client(self) -> Dict[str, Any]: return {"disallowedUpdateKeys": self.get_disallowed_update_keys()} class DefaultUserBackend(BaseUserBackend): """The default user backend for OpenSlides""" @property def name(self) -> str: return "default" def get_disallowed_update_keys(self) -> List[str]: return [] class UserBackendManager: """ Manages user backends. Can collect backends from app configs. """ def __init__(self): self.backends: Dict[str, BaseUserBackend] = {} def collect_backends_from_apps(self): """Iterate through app configs and get an optional "user_backend_class" for a backend""" for app in apps.get_app_configs(): user_backend_class = getattr(app, "user_backend_class", None) if user_backend_class: self.register_user_backend(user_backend_class()) def register_user_backend(self, backend: BaseUserBackend): """Registeres a user backend""" if backend.name in self.backends: raise UserBackendException( f"The user backend {backend.name} already exists." ) self.backends[backend.name] = backend logger.debug(f'Registered user backend "{backend.name}"') def get_backend(self, name: str) -> Optional[BaseUserBackend]: if name not in self.backends: all_backend_names = ", ".join(self.backends.keys()) raise UserBackendException( f'The backend "{name}" is not registered. All Backends: "{all_backend_names}"' ) return self.backends[name] def get_backends_for_client(self) -> Dict[str, Dict[str, Any]]: """Formats the backends for the client""" return {name: backend.for_client() for name, backend in self.backends.items()} user_backend_manager = UserBackendManager()