qutebrowser/qutebrowser/commands/argparser.py
2018-02-05 12:19:50 +01:00

165 lines
5.0 KiB
Python

# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
# Copyright 2014-2018 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# This file is part of qutebrowser.
#
# qutebrowser is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# qutebrowser is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with qutebrowser. If not, see <http://www.gnu.org/licenses/>.
"""argparse.ArgumentParser subclass to parse qutebrowser commands."""
import argparse
from PyQt5.QtCore import QUrl
from qutebrowser.commands import cmdexc
from qutebrowser.utils import utils, objreg, log
SUPPRESS = argparse.SUPPRESS
class ArgumentParserError(Exception):
"""Exception raised when the ArgumentParser signals an error."""
class ArgumentParserExit(Exception):
"""Exception raised when the argument parser exited.
Attributes:
status: The exit status.
"""
def __init__(self, status, msg):
self.status = status
super().__init__(msg)
class HelpAction(argparse.Action):
"""Argparse action to open the help page in the browser.
This is horrible encapsulation, but I can't think of a good way to do this
better...
"""
def __call__(self, parser, _namespace, _values, _option_string=None):
tabbed_browser = objreg.get('tabbed-browser', scope='window',
window='last-focused')
tabbed_browser.tabopen(
QUrl('qute://help/commands.html#{}'.format(parser.name)))
parser.exit()
class ArgumentParser(argparse.ArgumentParser):
"""Subclass ArgumentParser to be more suitable for runtime parsing.
Attributes:
name: The command name.
"""
def __init__(self, name, *args, **kwargs):
self.name = name
super().__init__(*args, add_help=False, prog=name, **kwargs)
def exit(self, status=0, message=None):
raise ArgumentParserExit(status, message)
def error(self, message):
raise ArgumentParserError(message.capitalize())
def arg_name(name):
"""Get the name an argument should have based on its Python name."""
return name.rstrip('_').replace('_', '-')
def _check_choices(param, value, choices):
if value not in choices:
expected_values = ', '.join(arg_name(val) for val in choices)
raise cmdexc.ArgumentTypeError("{}: Invalid value {} - expected "
"one of: {}".format(
param.name, value, expected_values))
def type_conv(param, typ, value, *, str_choices=None):
"""Convert a value based on a type.
Args:
param: The argparse.Parameter we're checking
types: The allowed type
value: The value to convert
str_choices: The allowed choices if the type ends up being a string
Return:
The converted value
"""
if isinstance(typ, str):
raise TypeError("{}: Legacy string type!".format(param.name))
if value is param.default:
return value
assert isinstance(value, str), repr(value)
if utils.is_enum(typ):
_check_choices(param, value, [arg_name(e.name) for e in typ])
return typ[value.replace('-', '_')]
elif typ is str:
if str_choices is not None:
_check_choices(param, value, str_choices)
return value
elif callable(typ):
# int, float, etc.
try:
return typ(value)
except (TypeError, ValueError):
msg = '{}: Invalid {} value {}'.format(
param.name, typ.__name__, value)
raise cmdexc.ArgumentTypeError(msg)
else:
raise ValueError("{}: Unknown type {!r}!".format(param.name, typ))
def multitype_conv(param, types, value, *, str_choices=None):
"""Convert a value based on a choice of types.
Args:
param: The inspect.Parameter we're checking
types: The allowed types ("overloads")
value: The value to convert
str_choices: The allowed choices if the type ends up being a string
Return:
The converted value
"""
types = list(set(types))
if str in types:
# Make sure str is always the last type in the list, so e.g. '23' gets
# returned as 23 if we have typing.Union[str, int]
types.remove(str)
types.append(str)
for typ in types:
log.commands.debug("Trying to parse {!r} as {}".format(value, typ))
try:
return type_conv(param, typ, value, str_choices=str_choices)
except cmdexc.ArgumentTypeError as e:
log.commands.debug("Got {} for {}".format(e, typ))
raise cmdexc.ArgumentTypeError('{}: Invalid value {}'.format(
param.name, value))