from typing import Any, Dict, Generator, Optional, Type class ProjectorElement: """ Base class for an element on the projector. Every app which wants to add projector elements has to create classes subclassing from this base class with different names. The name attribute has to be set. """ name: Optional[str] = None def check_and_update_data(self, projector_object: Any, config_entry: Any) -> Any: """ Checks projector element data via self.check_data() and updates them via self.update_data(). The projector object and the config entry have to be given. """ self.projector_object = projector_object self.config_entry = config_entry assert self.config_entry.get('name') == self.name, ( 'To get data of a projector element, the correct config entry has to be given.') self.check_data() return self.update_data() or {} def check_data(self) -> None: """ Method can be overridden to validate projector element data. This may raise ProjectorException in case of an error. Default: Does nothing. """ pass def update_data(self) -> Dict[Any, Any]: """ Method can be overridden to update the projector element data output. This should return a dictonary. Use this for server calculated data which have to be forwared to the client. Default: Does nothing. """ pass projector_elements: Dict[str, ProjectorElement] = {} def register_projector_elements(elements: Generator[Type[ProjectorElement], None, None]) -> None: """ Registers projector elements for later use. Has to be called in the app.ready method. """ for AppProjectorElement in elements: element = AppProjectorElement() projector_elements[element.name] = element # type: ignore def get_all_projector_elements() -> Dict[str, ProjectorElement]: """ Returns all projector elements that where registered with register_projector_elements() """ return projector_elements