cliff/cliff/command.py

51 lines
1.3 KiB
Python

import abc
import argparse
import inspect
class Command(object):
"""Base class for command plugins.
:param app: Application instance invoking the command.
:paramtype app: cliff.app.App
"""
__metaclass__ = abc.ABCMeta
def __init__(self, app, app_args):
self.app = app
self.app_args = app_args
return
def get_description(self):
"""Return the command description.
"""
return inspect.getdoc(self.__class__) or ''
def get_parser(self, prog_name):
"""Return an :class:`argparse.ArgumentParser`.
"""
parser = argparse.ArgumentParser(
description=self.get_description(),
prog=prog_name,
)
return parser
@abc.abstractmethod
def take_action(self, parsed_args):
"""Override to do something useful.
"""
def run(self, parsed_args):
"""Invoked by the application when the command is run.
Developers implementing commands should override
:meth:`take_action`.
Developers creating new command base classes (such as
:class:`Lister` and :class:`ShowOne`) should override this
method to wrap :meth:`take_action`.
"""
self.take_action(parsed_args)
return 0