Source code for modloader

	Modification loader class code for ScalyMUCK. This class
	is used to store and track loaded modifications that
	are in use by the server application

	Copyright (c) 2013 Robert MacGregor
	This software is licensed under the GNU General
	Public License version 3. Please refer to gpl.txt 
	for more information.

import logging
import inspect
import importlib

import settings

logger = logging.getLogger('Mods')
[docs]class ModLoader: """ Mod loading class for ScalyMUCK. """ workdir = None world = None interface = None session = None permissions = None commands = { } """ A dictionary of all loaded commands. The keys are the actual name a command is referred to by and said keys point to Python functions to be called upon use. """ modifications = { } """ A dictionary of all loaded modifications. The keys are the internal name of the mod and each key refers to a tuple with the following format: (instance, module). """
[docs] def __init__(self, world=None, interface=None, session=None, workdir=None, permissions=None): """ Initializes an instance of the ScalyMUCK mod loader. There are several keyword arguments that should be used with this __init__ command: * world -- An instance of the game.World object to be used with this ModLoader. * interface -- An instance of the game.Interface object to be used with this ModLoader. * session -- An active database session from SQLAlchemy to be used with this ModLoader. * workdir -- The work directory of the current running application. * permissions -- An instance of the game.Permissions object to be used with this ModLoader. """ self.workdir = workdir = world self.interface = interface self.session = session self.permissions = permissions self.set_defaults()
[docs] def load(self, modifications): """ Loads a semicolon deliminated list of modifications from application/game. If any of the specified modifications happen to already be loaded into ScalyMUCK, they are merely reloaded so that any changes made since the last load will be applied and take affect. NOTE: If there happens to be a low-level Python error (IE: SyntaxError) then the server application will merely crash as of the moment. Same goes for any internal errors in a mod code base that happen to raise an exception that is not derived from one of the exception classes in game.Exception. """ for mod_name in modifications.split(';'): mod_name = mod_name.lower() if (mod_name in self.modifications): # Reloads the modification module = self.modifications[mod_name] modules = inspect.getmembers(module, inspect.ismodule) for name, sub_module in modules: reload(sub_module) module = reload(module) modification = module.Modification(config=self.config,, interface=self.interface, session=self.session, permissions=self.permissions, modloader=self) self.modifications[mod_name] = (instance, module) else: try: module = importlib.import_module('game.%s' % (mod_name)) except ImportError as e: self.logger.warning(str(e)) return False else: config = settings.Settings('%s/config/%s.cfg' % (self.workdir, mod_name)) modification = module.Modification(config=config,, interface=self.interface, session=self.session, permissions=self.permissions, modloader=self) self.modifications.setdefault(mod_name, (modification, module)) commands = modification.get_commands()'Processed modification %s.' % (mod_name)) # Process aliases first aliases = { } for command in commands: for alias in commands[command]['aliases']: aliases.setdefault(alias, commands[command]) commands.update(aliases) # Then process the dictionary for command in commands: commands[command]['modification'] = mod_name if (command in self.commands): logger.warn('Overlapping command definitions for command "%s"! %s -> %s' % (command, mod_name, self.commands[command]['modification'])) self.commands.update(commands) self.set_defaults() return True
[docs] def set_defaults(self): """ This command merely makes sure that the core commands are loaded. It should be called everytime a modification is loaded in order to guarantee that a modification doesn't attempt to overwrite the core commands, even though by standard they shouldn't be defining these commands in the first place. """ self.commands['mods'] = { } self.commands['mods']['command'] = self.command_mods self.commands['mods']['description'] = 'Lists all loaded mods.' self.commands['mods']['usage'] = 'mods' self.commands['mods']['privilege'] = 3 self.commands['mods']['modification'] = '<CORE>' self.commands['load'] = { } self.commands['load']['command'] = self.command_load self.commands['load']['description'] = 'Loads the specified mod.' self.commands['load']['usage'] = 'load <name>' self.commands['load']['privilege'] = 3 self.commands['load']['modification'] = '<CORE>' self.commands['unload'] = { } self.commands['unload']['command'] = self.command_unload self.commands['unload']['description'] = 'Unloads the specified mod.' self.commands['unload']['usage'] = 'unload <name>' self.commands['unload']['privilege'] = 3 self.commands['unload']['modification'] = '<CORE>'
[docs] def find_command(self, name): """ Returns a command by name. """ if (name not in self.commands): return None else: return self.commands[name] # CORE Commands
[docs] def command_mods(self, **kwargs): """ Internal command to list installed mods. """ sender = kwargs['sender'] loaded = '' sender.send('Loaded modifications: ') for key in self.modifications.keys(): loaded += '%s, ' % (key) sender.send(loaded.rstrip(', '))
[docs] def command_load(self, **kwargs): """ Internal command to load mods. """ sender = kwargs['sender'] input = kwargs['input'].lower() if (input.strip() == ' '): sender.send('No input.') if (self.load(input) is False): sender.send('Failed to load mod "%s".' % (input)) else: sender.send('Loaded mod "%s".' % (input))
[docs] def command_unload(self, **kwargs): """ Internal command to unload mods. """ sender = kwargs['sender'] input = kwargs['input'].lower() if (input in self.modifications): instance, module = self.modifications[input] self.modifications.pop(input) commands = instance.get_commands() for command in commands.keys(): self.commands.pop(command) sender.send('Mod "%s" unloaded.' % (input)) else: sender.send('Unknown modification.')