from __future__ import annotations
import inspect
from functools import wraps
from typing import Any, Callable
from reactpy.core.types import ComponentType, VdomDict
[docs]def component(
function: Callable[..., ComponentType | VdomDict | str | None],
) -> Callable[..., Component]:
"""A decorator for defining a new component.
Parameters:
function: The component's :meth:`reactpy.core.proto.ComponentType.render` function.
"""
sig = inspect.signature(function)
if "key" in sig.parameters and sig.parameters["key"].kind in (
inspect.Parameter.KEYWORD_ONLY,
inspect.Parameter.POSITIONAL_OR_KEYWORD,
):
msg = f"Component render function {function} uses reserved parameter 'key'"
raise TypeError(msg)
@wraps(function)
def constructor(*args: Any, key: Any | None = None, **kwargs: Any) -> Component:
return Component(function, key, args, kwargs, sig)
return constructor
[docs]class Component:
"""An object for rending component models."""
__slots__ = "__weakref__", "_func", "_args", "_kwargs", "_sig", "key", "type"
def __init__(
self,
function: Callable[..., ComponentType | VdomDict | str | None],
key: Any | None,
args: tuple[Any, ...],
kwargs: dict[str, Any],
sig: inspect.Signature,
) -> None:
self.key = key
self.type = function
self._args = args
self._kwargs = kwargs
self._sig = sig
def render(self) -> ComponentType | VdomDict | str | None:
return self.type(*self._args, **self._kwargs)
def __repr__(self) -> str:
try:
args = self._sig.bind(*self._args, **self._kwargs).arguments
except TypeError:
return f"{self.type.__name__}(...)"
else:
items = ", ".join(f"{k}={v!r}" for k, v in args.items())
if items:
return f"{self.type.__name__}({id(self):02x}, {items})"
else:
return f"{self.type.__name__}({id(self):02x})"