boss.factory - heros-boss 0.5.1 documentation

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# Source code for boss.factory

    from heros import LocalHERO, LocalDatasourceHERO, PolledLocalDatasourceHERO
    from .helper import get_class_by_name, log, extend_none_allowed_list

    import asyncio
    from abc import abstractmethod
    from typing import Any, Callable

    class Factory:

        @classmethod
        def _build(
            cls,
            classname: str,
            name: str,
            arg_dict: dict | None = None,
            extra_decorators: dict | None = None,
            realm="heros",
            session_manager=None,
            tags: list | None = None,
        ):
            arg_dict = arg_dict or {}
            extra_decorators = extra_decorators or {}
            log.debug(f"building object of class {classname}")

            # if mixin classes are defined, we have to generate a modified class with the mixins
            tmp_classname = f"{classname}_HERO"
            log.debug(f"adding LocalHERO mixin to {classname} -> {tmp_classname}")

            # apply custom decortors to methods of the source class
            # how this is done is up to the mixin-class specific implementations
            source_class = get_class_by_name(classname)
            source_class = cls._decorate_methods(source_class, extra_decorators)

            target_class = type(
                tmp_classname,
                (
                    source_class,
                    cls._mixin_class,
                ),
                {},
            )

            # we need to replace the constructor to call the constructor of all super classes
            target_class.__init__ = cls._get_init_replacement(classname, name, realm, session_manager, tags)

            return target_class(**arg_dict)

        @classmethod
        @abstractmethod
        def _get_init_replacement(
            cls, classname: str, name: str, realm: str, session_manager, tags: list | None
        ) -> Callable:
            return lambda x: x

        @staticmethod
        def _decorate_methods(source_class: Any, extra_decorators: list[tuple[str, str]]) -> Any:
            """
            Wrap methods on the class before instantiation.
            """
            for method_name, decorator_path in extra_decorators:
                log.debug(f"Decorating {source_class}.{method_name} with {decorator_path}")
                module, _, _decorator_name = decorator_path.rpartition(".")
                if not module:
                    log.error(f"Invalid decorator path: '{decorator_path}' — must include module and name!")
                    continue
                try:
                    deco = get_class_by_name(decorator_path)
                except (ImportError, AttributeError):
                    log.exception(f"Could not load module {decorator_path} for decoration!")
                    continue
                method = getattr(source_class, method_name, None)
                if method is None:
                    log.error(f"Could not decorate! {method_name} is no method of {source_class}!")
                    continue
                setattr(source_class, method_name, deco(method))
            return source_class

    class HEROFactory(Factory):
        _mixin_class = LocalHERO

        @classmethod
        def build(
            cls,
            classname: str,
            name: str,
            arg_dict: dict | None = None,
            extra_decorators: dict | None = None,
            realm="heros",
            session_manager=None,
            tags: list | None = None,
        ):
            arg_dict = arg_dict or {}
            extra_decorators = extra_decorators or {}
            return cls._build(classname, name, arg_dict, extra_decorators, realm, session_manager, tags)

        @classmethod
        def _get_init_replacement(
            cls, classname: str, name: str, realm: str, session_manager, tags: list | None
        ) -> Callable:
            def _init_replacement(
                self, *args, _realm=realm, _session_manager=session_manager, _tags: list | None = None, **kwargs
            ):
                get_class_by_name(classname).__init__(self, *args, **kwargs)
                _tags = extend_none_allowed_list(_tags, tags)
                cls._mixin_class.__init__(self, name, realm=_realm, session_manager=_session_manager, tags=_tags)

            return _init_replacement

    class DatasourceHEROFactory(HEROFactory):
        _mixin_class = LocalDatasourceHERO

        @classmethod
        def build(
            cls,
            classname: str,
            name: str,
            arg_dict: dict | None = None,
            extra_decorators: dict | None = None,
            observables: dict | None = None,
            realm="heros",
            session_manager=None,
            tags: list | None = None,
        ):
            arg_dict = arg_dict or {}
            extra_decorators = extra_decorators or {}
            observables = observables or {}
            cls._observables = observables
            return cls._build(classname, name, arg_dict, extra_decorators, realm, session_manager, tags)

        @classmethod
        def _get_init_replacement(
            cls, classname: str, name: str, realm: str, session_manager, tags: list | None
        ) -> Callable:
            def _init_replacement(
                self, *args, _realm=realm, _session_manager=session_manager, _tags: list | None = None, **kwargs
            ):
                get_class_by_name(classname).__init__(self, *args, **kwargs)
                _tags = extend_none_allowed_list(_tags, tags)
                cls._mixin_class.__init__(
                    self, name, realm=_realm, session_manager=_session_manager, tags=_tags, observables=cls._observables
                )

            return _init_replacement

    class PolledDatasourceHEROFactory(Factory):
        _mixin_class = PolledLocalDatasourceHERO

        @classmethod
        def build(
            cls,
            classname: str,
            name: str,
            arg_dict: dict | None = None,
            extra_decorators: dict | None = None,
            loop: asyncio.AbstractEventLoop = asyncio.new_event_loop(),
            interval: float = 5,
            observables: dict | None = None,
            realm="heros",
            session_manager=None,
            tags: list | None = None,
        ):
            arg_dict = arg_dict or {}
            extra_decorators = extra_decorators or {}
            observables = observables or {}
            cls._loop = loop
            cls._interval = interval
            cls._observables = observables
            return cls._build(classname, name, arg_dict, extra_decorators, realm, session_manager, tags)

        @classmethod
        def _get_init_replacement(
            cls, classname: str, name: str, realm: str, session_manager, tags: list | None
        ) -> Callable:
            def _init_replacement(
                self, *args, _realm=realm, _session_manager=session_manager, _tags: list | None = None, **kwargs
            ):
                get_class_by_name(classname).__init__(self, *args, **kwargs)
                _tags = extend_none_allowed_list(_tags, tags)
                cls._mixin_class.__init__(
                    self,
                    name,
                    realm=_realm,
                    loop=cls._loop,
                    interval=cls._interval,
                    session_manager=_session_manager,
                    observables=cls._observables,
                    tags=_tags,
                )

            return _init_replacement