Current File : //opt/alt/python35/lib/python3.5/site-packages/click/decorators.py
import sys
import inspect
from functools import update_wrapper
from ._compat import iteritems
from ._unicodefun import _check_for_unicode_literals
from .utils import echo
from .globals import get_current_context
def pass_context(f):
"""Marks a callback as wanting to receive the current context
object as first argument.
"""
def new_func(*args, **kwargs):
return f(get_current_context(), *args, **kwargs)
return update_wrapper(new_func, f)
def pass_obj(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):
return f(get_current_context().obj, *args, **kwargs)
return update_wrapper(new_func, f)
def make_pass_decorator(object_type, ensure=False):
"""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):
def new_func(*args, **kwargs):
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 object of type %r existing'
% object_type.__name__)
return ctx.invoke(f, obj, *args[1:], **kwargs)
return update_wrapper(new_func, f)
return decorator
def _make_command(f, name, attrs, cls):
if isinstance(f, Command):
raise TypeError('Attempted to convert a callback into a '
'command twice.')
try:
params = f.__click_params__
params.reverse()
del f.__click_params__
except AttributeError:
params = []
help = attrs.get('help')
if help is None:
help = inspect.getdoc(f)
if isinstance(help, bytes):
help = help.decode('utf-8')
else:
help = inspect.cleandoc(help)
attrs['help'] = help
_check_for_unicode_literals()
return cls(name=name or f.__name__.lower(),
callback=f, params=params, **attrs)
def command(name=None, cls=None, **attrs):
"""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. 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.
:param cls: the command class to instantiate. This defaults to
:class:`Command`.
"""
if cls is None:
cls = Command
def decorator(f):
cmd = _make_command(f, name, attrs, cls)
cmd.__doc__ = f.__doc__
return cmd
return decorator
def group(name=None, **attrs):
"""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 command(name, **attrs)
def _param_memo(f, param):
if isinstance(f, Command):
f.params.append(param)
else:
if not hasattr(f, '__click_params__'):
f.__click_params__ = []
f.__click_params__.append(param)
def argument(*param_decls, **attrs):
"""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):
ArgumentClass = attrs.pop('cls', Argument)
_param_memo(f, ArgumentClass(param_decls, **attrs))
return f
return decorator
def option(*param_decls, **attrs):
"""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):
if 'help' in attrs:
attrs['help'] = inspect.cleandoc(attrs['help'])
OptionClass = attrs.pop('cls', Option)
_param_memo(f, OptionClass(param_decls, **attrs))
return f
return decorator
def confirmation_option(*param_decls, **attrs):
"""Shortcut for confirmation prompts that can be ignored by passing
``--yes`` as parameter.
This is equivalent to decorating a function with :func:`option` with
the following parameters::
def callback(ctx, param, value):
if not value:
ctx.abort()
@click.command()
@click.option('--yes', is_flag=True, callback=callback,
expose_value=False, prompt='Do you want to continue?')
def dropdb():
pass
"""
def decorator(f):
def callback(ctx, param, value):
if not value:
ctx.abort()
attrs.setdefault('is_flag', True)
attrs.setdefault('callback', callback)
attrs.setdefault('expose_value', False)
attrs.setdefault('prompt', 'Do you want to continue?')
attrs.setdefault('help', 'Confirm the action without prompting.')
return option(*(param_decls or ('--yes',)), **attrs)(f)
return decorator
def password_option(*param_decls, **attrs):
"""Shortcut for password prompts.
This is equivalent to decorating a function with :func:`option` with
the following parameters::
@click.command()
@click.option('--password', prompt=True, confirmation_prompt=True,
hide_input=True)
def changeadmin(password):
pass
"""
def decorator(f):
attrs.setdefault('prompt', True)
attrs.setdefault('confirmation_prompt', True)
attrs.setdefault('hide_input', True)
return option(*(param_decls or ('--password',)), **attrs)(f)
return decorator
def version_option(version=None, *param_decls, **attrs):
"""Adds a ``--version`` option which immediately ends the program
printing out the version number. This is implemented as an eager
option that prints the version and exits the program in the callback.
:param version: the version number to show. If not provided Click
attempts an auto discovery via setuptools.
:param prog_name: the name of the program (defaults to autodetection)
:param message: custom message to show instead of the default
(``'%(prog)s, version %(version)s'``)
:param others: everything else is forwarded to :func:`option`.
"""
if version is None:
module = sys._getframe(1).f_globals.get('__name__')
def decorator(f):
prog_name = attrs.pop('prog_name', None)
message = attrs.pop('message', '%(prog)s, version %(version)s')
def callback(ctx, param, value):
if not value or ctx.resilient_parsing:
return
prog = prog_name
if prog is None:
prog = ctx.find_root().info_name
ver = version
if ver is None:
try:
import pkg_resources
except ImportError:
pass
else:
for dist in pkg_resources.working_set:
scripts = dist.get_entry_map().get('console_scripts') or {}
for script_name, entry_point in iteritems(scripts):
if entry_point.module_name == module:
ver = dist.version
break
if ver is None:
raise RuntimeError('Could not determine version')
echo(message % {
'prog': prog,
'version': ver,
}, color=ctx.color)
ctx.exit()
attrs.setdefault('is_flag', True)
attrs.setdefault('expose_value', False)
attrs.setdefault('is_eager', True)
attrs.setdefault('help', 'Show the version and exit.')
attrs['callback'] = callback
return option(*(param_decls or ('--version',)), **attrs)(f)
return decorator
def help_option(*param_decls, **attrs):
"""Adds a ``--help`` option which immediately ends the program
printing out the help page. This is usually unnecessary to add as
this is added by default to all commands unless suppressed.
Like :func:`version_option`, this is implemented as eager option that
prints in the callback and exits.
All arguments are forwarded to :func:`option`.
"""
def decorator(f):
def callback(ctx, param, value):
if value and not ctx.resilient_parsing:
echo(ctx.get_help(), color=ctx.color)
ctx.exit()
attrs.setdefault('is_flag', True)
attrs.setdefault('expose_value', False)
attrs.setdefault('help', 'Show this message and exit.')
attrs.setdefault('is_eager', True)
attrs['callback'] = callback
return option(*(param_decls or ('--help',)), **attrs)(f)
return decorator
# Circular dependencies between core and decorators
from .core import Command, Group, Argument, Option
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