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
[docs]
class Factory:
[docs]
@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)
[docs]
@classmethod
@abstractmethod
def _get_init_replacement(
cls, classname: str, name: str, realm: str, session_manager, tags: list | None
) -> Callable:
return lambda x: x
[docs]
@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
[docs]
class HEROFactory(Factory):
_mixin_class = LocalHERO
[docs]
@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)
[docs]
@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
[docs]
class DatasourceHEROFactory(HEROFactory):
_mixin_class = LocalDatasourceHERO
[docs]
@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)
[docs]
@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
[docs]
class PolledDatasourceHEROFactory(Factory):
_mixin_class = PolledLocalDatasourceHERO
[docs]
@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)
[docs]
@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