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Edit File: decorators.py
import inspect import types import typing as t from functools import update_wrapper from gettext import gettext as _ from .core import Argument from .core import Command from .core import Context from .core import Group from .core import Option from .core import Parameter from .globals import get_current_context from .utils import echo F = t.TypeVar("F", bound=t.Callable[..., t.Any]) FC = t.TypeVar("FC", bound=t.Union[t.Callable[..., t.Any], Command]) def pass_context(f: F) -> F: """Marks a callback as wanting to receive the current context object as first argument. """ def new_func(*args, **kwargs): # type: ignore return f(get_current_context(), *args, **kwargs) return update_wrapper(t.cast(F, new_func), f) def pass_obj(f: F) -> F: """Similar to :func:`pass_context`, but only pass the object on the context onwards (:attr:`Context.obj`). This is useful if that object represents the state of a nested system. """ def new_func(*args, **kwargs): # type: ignore return f(get_current_context().obj, *args, **kwargs) return update_wrapper(t.cast(F, new_func), f) def make_pass_decorator( object_type: t.Type, ensure: bool = False ) -> "t.Callable[[F], F]": """Given an object type this creates a decorator that will work similar to :func:`pass_obj` but instead of passing the object of the current context, it will find the innermost context of type :func:`object_type`. This generates a decorator that works roughly like this:: from functools import update_wrapper def decorator(f): @pass_context def new_func(ctx, *args, **kwargs): obj = ctx.find_object(object_type) return ctx.invoke(f, obj, *args, **kwargs) return update_wrapper(new_func, f) return decorator :param object_type: the type of the object to pass. :param ensure: if set to `True`, a new object will be created and remembered on the context if it's not there yet. """ def decorator(f: F) -> F: def new_func(*args, **kwargs): # type: ignore ctx = get_current_context() if ensure: obj = ctx.ensure_object(object_type) else: obj = ctx.find_object(object_type) if obj is None: raise RuntimeError( "Managed to invoke callback without a context" f" object of type {object_type.__name__!r}" " existing." ) return ctx.invoke(f, obj, *args, **kwargs) return update_wrapper(t.cast(F, new_func), f) return decorator def pass_meta_key( key: str, *, doc_description: t.Optional[str] = None ) -> "t.Callable[[F], F]": """Create a decorator that passes a key from :attr:`click.Context.meta` as the first argument to the decorated function. :param key: Key in ``Context.meta`` to pass. :param doc_description: Description of the object being passed, inserted into the decorator's docstring. Defaults to "the 'key' key from Context.meta". .. versionadded:: 8.0 """ def decorator(f: F) -> F: def new_func(*args, **kwargs): # type: ignore ctx = get_current_context() obj = ctx.meta[key] return ctx.invoke(f, obj, *args, **kwargs) return update_wrapper(t.cast(F, new_func), f) if doc_description is None: doc_description = f"the {key!r} key from :attr:`click.Context.meta`" decorator.__doc__ = ( f"Decorator that passes {doc_description} as the first argument" " to the decorated function." ) return decorator CmdType = t.TypeVar("CmdType", bound=Command) @t.overload def command( __func: t.Callable[..., t.Any], ) -> Command: ... @t.overload def command( name: t.Optional[str] = None, **attrs: t.Any, ) -> t.Callable[..., Command]: ... @t.overload def command( name: t.Optional[str] = None, cls: t.Type[CmdType] = ..., **attrs: t.Any, ) -> t.Callable[..., CmdType]: ... def command( name: t.Union[str, t.Callable[..., t.Any], None] = None, cls: t.Optional[t.Type[Command]] = None, **attrs: t.Any, ) -> t.Union[Command, t.Callable[..., Command]]: r"""Creates a new :class:`Command` and uses the decorated function as callback. This will also automatically attach all decorated :func:`option`\s and :func:`argument`\s as parameters to the command. The name of the command defaults to the name of the function with underscores replaced by dashes. If you want to change that, you can pass the intended name as the first argument. All keyword arguments are forwarded to the underlying command class. For the ``params`` argument, any decorated params are appended to the end of the list. Once decorated the function turns into a :class:`Command` instance that can be invoked as a command line utility or be attached to a command :class:`Group`. :param name: the name of the command. This defaults to the function name with underscores replaced by dashes. :param cls: the command class to instantiate. This defaults to :class:`Command`. .. versionchanged:: 8.1 This decorator can be applied without parentheses. .. versionchanged:: 8.1 The ``params`` argument can be used. Decorated params are appended to the end of the list. """ func: t.Optional[t.Callable[..., t.Any]] = None if callable(name): func = name name = None assert cls is None, "Use 'command(cls=cls)(callable)' to specify a class." assert not attrs, "Use 'command(**kwargs)(callable)' to provide arguments." if cls is None: cls = Command def decorator(f: t.Callable[..., t.Any]) -> Command: if isinstance(f, Command): raise TypeError("Attempted to convert a callback into a command twice.") attr_params = attrs.pop("params", None) params = attr_params if attr_params is not None else [] try: decorator_params = f.__click_params__ # type: ignore except AttributeError: pass else: del f.__click_params__ # type: ignore params.extend(reversed(decorator_params)) if attrs.get("help") is None: attrs["help"] = f.__doc__ cmd = cls( # type: ignore[misc] name=name or f.__name__.lower().replace("_", "-"), # type: ignore[arg-type] callback=f, params=params, **attrs, ) cmd.__doc__ = f.__doc__ return cmd if func is not None: return decorator(func) return decorator @t.overload def group( __func: t.Callable[..., t.Any], ) -> Group: ... @t.overload def group( name: t.Optional[str] = None, **attrs: t.Any, ) -> t.Callable[[F], Group]: ... def group( name: t.Union[str, t.Callable[..., t.Any], None] = None, **attrs: t.Any ) -> t.Union[Group, t.Callable[[F], Group]]: """Creates a new :class:`Group` with a function as callback. This works otherwise the same as :func:`command` just that the `cls` parameter is set to :class:`Group`. .. versionchanged:: 8.1 This decorator can be applied without parentheses. """ if attrs.get("cls") is None: attrs["cls"] = Group if callable(name): grp: t.Callable[[F], Group] = t.cast(Group, command(**attrs)) return grp(name) return t.cast(Group, command(name, **attrs)) def _param_memo(f: FC, param: Parameter) -> None: if isinstance(f, Command): f.params.append(param) else: if not hasattr(f, "__click_params__"): f.__click_params__ = [] # type: ignore f.__click_params__.append(param) # type: ignore def argument(*param_decls: str, **attrs: t.Any) -> t.Callable[[FC], FC]: """Attaches an argument to the command. All positional arguments are passed as parameter declarations to :class:`Argument`; all keyword arguments are forwarded unchanged (except ``cls``). This is equivalent to creating an :class:`Argument` instance manually and attaching it to the :attr:`Command.params` list. :param cls: the argument class to instantiate. This defaults to :class:`Argument`. """ def decorator(f: FC) -> FC: ArgumentClass = attrs.pop("cls", None) or Argument _param_memo(f, ArgumentClass(param_decls, **attrs)) return f return decorator def option(*param_decls: str, **attrs: t.Any) -> t.Callable[[FC], FC]: """Attaches an option to the command. All positional arguments are passed as parameter declarations to :class:`Option`; all keyword arguments are forwarded unchanged (except ``cls``). This is equivalent to creating an :class:`Option` instance manually and attaching it to the :attr:`Command.params` list. :param cls: the option class to instantiate. This defaults to :class:`Option`. """ def decorator(f: FC) -> FC: # Issue 926, copy attrs, so pre-defined options can re-use the same cls= option_attrs = attrs.copy() OptionClass = option_attrs.pop("cls", None) or Option _param_memo(f, OptionClass(param_decls, **option_attrs)) return f return decorator def confirmation_option(*param_decls: str, **kwargs: t.Any) -> t.Callable[[FC], FC]: """Add a ``--yes`` option which shows a prompt before continuing if not passed. If the prompt is declined, the program will exit. :param param_decls: One or more option names. Defaults to the single value ``"--yes"``. :param kwargs: Extra arguments are passed to :func:`option`. """ def callback(ctx: Context, param: Parameter, value: bool) -> None: if not value: ctx.abort() if not param_decls: param_decls = ("--yes",) kwargs.setdefault("is_flag", True) kwargs.setdefault("callback", callback) kwargs.setdefault("expose_value", False) kwargs.setdefault("prompt", "Do you want to continue?") kwargs.setdefault("help", "Confirm the action without prompting.") return option(*param_decls, **kwargs) def password_option(*param_decls: str, **kwargs: t.Any) -> t.Callable[[FC], FC]: """Add a ``--password`` option which prompts for a password, hiding input and asking to enter the value again for confirmation. :param param_decls: One or more option names. Defaults to the single value ``"--password"``. :param kwargs: Extra arguments are passed to :func:`option`. """ if not param_decls: param_decls = ("--password",) kwargs.setdefault("prompt", True) kwargs.setdefault("confirmation_prompt", True) kwargs.setdefault("hide_input", True) return option(*param_decls, **kwargs) def version_option( version: t.Optional[str] = None, *param_decls: str, package_name: t.Optional[str] = None, prog_name: t.Optional[str] = None, message: t.Optional[str] = None, **kwargs: t.Any, ) -> t.Callable[[FC], FC]: """Add a ``--version`` option which immediately prints the version number and exits the program. If ``version`` is not provided, Click will try to detect it using :func:`importlib.metadata.version` to get the version for the ``package_name``. On Python < 3.8, the ``importlib_metadata`` backport must be installed. If ``package_name`` is not provided, Click will try to detect it by inspecting the stack frames. This will be used to detect the version, so it must match the name of the installed package. :param version: The version number to show. If not provided, Click will try to detect it. :param param_decls: One or more option names. Defaults to the single value ``"--version"``. :param package_name: The package name to detect the version from. If not provided, Click will try to detect it. :param prog_name: The name of the CLI to show in the message. If not provided, it will be detected from the command. :param message: The message to show. The values ``%(prog)s``, ``%(package)s``, and ``%(version)s`` are available. Defaults to ``"%(prog)s, version %(version)s"``. :param kwargs: Extra arguments are passed to :func:`option`. :raise RuntimeError: ``version`` could not be detected. .. versionchanged:: 8.0 Add the ``package_name`` parameter, and the ``%(package)s`` value for messages. .. versionchanged:: 8.0 Use :mod:`importlib.metadata` instead of ``pkg_resources``. The version is detected based on the package name, not the entry point name. The Python package name must match the installed package name, or be passed with ``package_name=``. """ if message is None: message = _("%(prog)s, version %(version)s") if version is None and package_name is None: frame = inspect.currentframe() f_back = frame.f_back if frame is not None else None f_globals = f_back.f_globals if f_back is not None else None # break reference cycle # https://docs.python.org/3/library/inspect.html#the-interpreter-stack del frame if f_globals is not None: package_name = f_globals.get("__name__") if package_name == "__main__": package_name = f_globals.get("__package__") if package_name: package_name = package_name.partition(".")[0] def callback(ctx: Context, param: Parameter, value: bool) -> None: if not value or ctx.resilient_parsing: return nonlocal prog_name nonlocal version if prog_name is None: prog_name = ctx.find_root().info_name if version is None and package_name is not None: metadata: t.Optional[types.ModuleType] try: from importlib import metadata # type: ignore except ImportError: # Python < 3.8 import importlib_metadata as metadata # type: ignore try: version = metadata.version(package_name) # type: ignore except metadata.PackageNotFoundError: # type: ignore raise RuntimeError( f"{package_name!r} is not installed. Try passing" " 'package_name' instead." ) from None if version is None: raise RuntimeError( f"Could not determine the version for {package_name!r} automatically." ) echo( t.cast(str, message) % {"prog": prog_name, "package": package_name, "version": version}, color=ctx.color, ) ctx.exit() if not param_decls: param_decls = ("--version",) kwargs.setdefault("is_flag", True) kwargs.setdefault("expose_value", False) kwargs.setdefault("is_eager", True) kwargs.setdefault("help", _("Show the version and exit.")) kwargs["callback"] = callback return option(*param_decls, **kwargs) def help_option(*param_decls: str, **kwargs: t.Any) -> t.Callable[[FC], FC]: """Add a ``--help`` option which immediately prints the help page and exits the program. This is usually unnecessary, as the ``--help`` option is added to each command automatically unless ``add_help_option=False`` is passed. :param param_decls: One or more option names. Defaults to the single value ``"--help"``. :param kwargs: Extra arguments are passed to :func:`option`. """ def callback(ctx: Context, param: Parameter, value: bool) -> None: if not value or ctx.resilient_parsing: return echo(ctx.get_help(), color=ctx.color) ctx.exit() if not param_decls: param_decls = ("--help",) kwargs.setdefault("is_flag", True) kwargs.setdefault("expose_value", False) kwargs.setdefault("is_eager", True) kwargs.setdefault("help", _("Show this message and exit.")) kwargs["callback"] = callback return option(*param_decls, **kwargs)