Current File : //usr/lib/python3/dist-packages/click/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", 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
def _make_command(
f: F,
name: t.Optional[str],
attrs: t.MutableMapping[str, t.Any],
cls: t.Type[Command],
) -> Command:
if isinstance(f, Command):
raise TypeError("Attempted to convert a callback into a command twice.")
try:
params = f.__click_params__ # type: ignore
params.reverse()
del f.__click_params__ # type: ignore
except AttributeError:
params = []
help = attrs.get("help")
if help is None:
help = inspect.getdoc(f)
else:
help = inspect.cleandoc(help)
attrs["help"] = help
return cls(
name=name or f.__name__.lower().replace("_", "-"),
callback=f,
params=params,
**attrs,
)
def command(
name: t.Optional[str] = None,
cls: t.Optional[t.Type[Command]] = None,
**attrs: t.Any,
) -> t.Callable[[F], 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.
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`.
"""
if cls is None:
cls = Command
def decorator(f: t.Callable[..., t.Any]) -> Command:
cmd = _make_command(f, name, attrs, cls) # type: ignore
cmd.__doc__ = f.__doc__
return cmd
return decorator
def group(name: t.Optional[str] = None, **attrs: t.Any) -> 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`.
"""
attrs.setdefault("cls", Group)
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", 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()
if "help" in option_attrs:
option_attrs["help"] = inspect.cleandoc(option_attrs["help"])
OptionClass = option_attrs.pop("cls", 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)
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