def __init__(self, component_class: Type[_ComponentType], **kwargs):
if utils.is_component_instance(component_class):
raise TypeError(
"`PartialComponent` must be passed component classes, not component "
f"instances. Received: {repr(component_class)}")
if not utils.is_component_class(component_class):
raise TypeError(
"The class passed to `PartialComponent` must be a component class. "
f"Received: {component_class}.")
if len(kwargs) == 0:
raise TypeError(
"`PartialComponent` must receive at least one keyword argument."
)
lazy_kwargs = {}
for name, value in kwargs.items():
if name not in component_class.__component_fields__:
raise TypeError(
f"Keyword argument '{name}' passed to `PartialComponent` does "
"not correspond to any field of component class "
f"'{component_class.__name__}'.")
if utils.is_immutable(value):
lazy_kwargs[name] = utils.wrap_in_callable(value)
else:
if not inspect.isfunction(value):
raise _kwargs_error
if len(inspect.signature(value).parameters) == 0:
lazy_kwargs[name] = value
else:
raise _kwargs_error
self._component_class = component_class
self._lazy_kwargs = lazy_kwargs
def __init__(
self,
default: Union[
utils.Missing, F, Callable[[], F], Callable[[C], F]
] = utils.missing,
*, # `allow_missing` must be a keyword argument.
allow_missing: bool = False,
):
# Define here once to avoid having to define twice below.
default_error = TypeError(
"If `default` is passed to `Field`, it must be either:\n"
"- An immutable value (int, float, bool, string, or None).\n"
"- A function or lambda accepting no arguments or a single\n"
" argument (`self`), and returning the default value.\n"
f"Received: {default}."
)
self.name = None
self.allow_missing = allow_missing
self.host_component_class = None
self.type = None
self._registered = False
self._return_annotation = inspect.Signature.empty
if allow_missing and default is not utils.missing:
raise ValueError(
"If a `Field` has `allow_missing=True`, no default can be provided."
)
if default is utils.missing or utils.is_immutable(default):
self._default = default
return
if inspect.isfunction(default):
signature = inspect.signature(default)
if len(signature.parameters) > 1 or (
len(signature.parameters) == 1
and list(signature.parameters.values())[0].kind
in (inspect.Parameter.VAR_POSITIONAL, inspect.Parameter.VAR_KEYWORD)
):
raise default_error
self._default = default
self._return_annotation = signature.return_annotation
return
raise default_error