Source code for lmi.scripts.common.command.multiplexer

# Copyright (C) 2013-2014 Michal Minar <>
# This program 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 2
# of the License, or (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program; if not, see <>.
Defines command class used to nest multiple commands under one.

from docopt import docopt

from lmi.scripts.common import get_logger
from lmi.scripts.common.command import base
from lmi.scripts.common.command import meta

LOG = get_logger(__name__)

[docs]class LmiCommandMultiplexer(base.LmiBaseCommand): """ Base class for node commands. It consumes just part of command line arguments and passes the remainder to one of its subcommands. Example usage: :: class MyCommand(LmiCommandMultiplexer): ''' My command description. Usage: %(cmd)s mycommand (subcmd1 | subcmd2) ''' COMMANDS = {'subcmd1' : Subcmd1, 'subcmd2' : Subcmd2} Where ``Subcmd1`` and ``Subcmd2`` are some other ``LmiBaseCommand`` subclasses. Documentation string must be parseable with ``docopt``. Recognized properties: ``COMMANDS`` : ``dictionary`` property will be translated to :py:meth:`LmiCommandMultiplexer.child_commands` class method by :py:class:`~.meta.MultiplexerMetaClass`. Using metaclass: :py:class:`.meta.MultiplexerMetaClass`. """ __metaclass__ = meta.MultiplexerMetaClass @classmethod
[docs] def child_commands(cls): """ Abstract class method, that needs to be implemented in subclass. This is done by associated meta-class, when defining a command with assigned ``COMMANDS`` property. :returns: Dictionary of subcommand names with assigned command factories. :rtype: dictionary """ raise NotImplementedError("child_commands must be implemented in" " a subclass")
[docs] def fallback_command(cls): """ This is overriden by :py:class:`~.meta.MultiplexerMetaClass` when the ``FALLBACK_COMMAND`` gets processed. :returns: Command factory invoked for missing command on command line. :rtype: :py:class:`~.endpoint.LmiEndPointCommand` """ return None
@classmethod def is_end_point(cls): return False
[docs] def run_subcommand(self, cmd_name, args): """ Pass control to a subcommand identified by given name. :param string cmd_name: Name of direct subcommand, whose :py:meth:`` method shall be invoked. :param list args: List of arguments for particular subcommand. :returns: Application exit code. :rtype: integer """ if not isinstance(cmd_name, basestring): raise TypeError("cmd_name must be a string, not %s" % repr(cmd_name)) if not isinstance(args, (list, tuple)): raise TypeError("args must be a list, not %s" % repr(args)) try: cmd_cls = self.child_commands()[cmd_name] cmd = cmd_cls(, cmd_name, self) except KeyError: LOG().critical('Unexpected command "%s".', cmd_name) return 1 return
[docs] def run(self, args): """ Handle optional parameters, retrieve desired subcommand name and pass the remainder of arguments to it. :param list args: List of arguments with at least subcommand name. """ if not isinstance(args, (list, tuple)): raise TypeError("args must be a list") full_args = self.get_cmd_name_parts(for_docopt=True) + args docopt_kwargs = { # check the --help ourselves (the default docopt behaviour checks # also for --version) 'help' : False, # let's ignore options following first command for generated # usage string and when a height of this branch is > 2 'options_first' : not self.has_own_usage() or any( not cmd.is_end_point() for cmd in self.child_commands().values() if not args or args[0] not in self.child_commands() or self.child_commands()[args[0]] is cmd) } options = docopt(self.get_usage(), full_args, **docopt_kwargs) if options.pop('--help', False) or (args and args[0] == '--help'): return 0 if ( self.fallback_command() is not None and (not args or args[0] not in self.child_commands())): cmd_cls = self.fallback_command() cmd = cmd_cls(, self.cmd_name, self.parent) return return self.run_subcommand(args[0], args[1:])