""" Command handler This module contains the infrastructure for accepting commands on the command line. The process is as follows: 1) The calling object (caller) inputs a string and triggers the command parsing system. 2) The system checks the state of the caller - loggedin or not 3) Depending on the login/not state, it collects cmdsets from different sources: not logged in - uses the single cmdset in settings.CMDSET_UNLOGGEDIN normal - gathers command sets from many different sources (shown in dropping priority): channels - all available channel names are auto-created into a cmdset, to allow for giving the channel name and have the following immediately sent to the channel. The sending is performed by the CMD_CHANNEL system command. exits - exits from a room are dynamically made into a cmdset for matching, allowing the player to give just the name and thus traverse the exit. If a match, the traversing is handled by the CMD_EXIT system command. object cmdsets - all objects at caller's location are scanned for non-empty cmdsets. caller - the caller is searched for its currently active cmdset. 4) All the gathered cmdsets (if more than one) are merged into one using the cmdset priority rules. 5) If no cmdsets where found, we raise NoCmdSet exception. This should not happen, at least the caller should have a default cmdset available at all times. --> Finished 6) The raw input string is parsed using the parser defined by settings.CMDPARSER. It returns a special match object since a command may consist of many space-separated words and we thus have to match them all. 7) If no command was supplied, we search the merged cmdset for system command CMD_NOINPUT and branches to execute that. --> Finished 8) We match the the match object against the merged cmdset and the eventual priorities given it by the parser. The result is a list of command matches tied to their respective match object. 9) If we found no matches, branch to system command CMD_NOMATCH --> Finished 10) If we were unable to weed out multiple matches, branch CMD_MULTIMATCH --> Finished 11) We analyze the matched command to determine if it is a channel-type command, that is a command auto-created to represent a valid comm channel. If so, we see if CMD_CHANNEL is custom-defined in the merged cmdset, or we launch the auto-created command direclty --> Finished 12 We next check if this is an exit-type command, that is, a command auto-created to represent an exit from this room. If so we check for custom CMD_EXIT in cmdset or launch the auto-generated command directly --> Finished 13) At this point we have found a normal command. We assign useful variables to it, that will be available to the command coder at run-time. When launching the command (normal, or system command both), two hook functions are called in sequence, cmd.parse() followed by cmd.func(). It's up to the implementation as to how to use this to most advantage. """ from traceback import format_exc from django.conf import settings from src.comms.channelhandler import CHANNELHANDLER from src.commands.cmdsethandler import import_cmdset from src.utils import logger, utils from src.commands.cmdparser import at_multimatch_cmd #This switches the command parser to a user-defined one. # You have to restart the server for this to take effect. COMMAND_PARSER = utils.mod_import(*settings.COMMAND_PARSER.rsplit('.', 1)) # There are a few system-hardcoded command names. These # allow for custom behaviour when the command handler hits # special situations -- it then calls a normal Command # that you can customize! CMD_NOINPUT = "__noinput_command" CMD_NOMATCH = "__nomatch_command" CMD_MULTIMATCH = "__multimatch_command" CMD_CHANNEL = "__send_to_channel" class NoCmdSets(Exception): "No cmdsets found. Critical error." pass class ExecSystemCommand(Exception): "Run a system command" def __init__(self, syscmd, sysarg): self.args = (syscmd, sysarg) # needed by exception error handling self.syscmd = syscmd self.sysarg = sysarg def get_and_merge_cmdsets(caller): """ Gather all relevant cmdsets and merge them. Note that this is only relevant for logged-in callers. """ # The calling object's cmdset try: caller_cmdset = caller.cmdset.current except AttributeError: caller_cmdset = None # Create cmdset for all player's available channels channel_cmdset = None if not caller_cmdset.no_channels: channel_cmdset = CHANNELHANDLER.get_cmdset(caller) # Gather cmdsets from location, objects in location or carried local_objects_cmdsets = [None] location = None if hasattr(caller, "location"): location = caller.location if location and not caller_cmdset.no_objs: # Gather all cmdsets stored on objects in the room and # also in the caller's inventory and the location itself local_objlist = location.contents_get(exclude=caller.dbobj) + caller.contents + [location] local_objects_cmdsets = [obj.cmdset.current for obj in local_objlist if (obj.cmdset.current and obj.locks.check(caller, 'call', no_superuser_bypass=True))] for cset in local_objects_cmdsets: #This is necessary for object sets, or we won't be able to separate #the command sets from each other in a busy room. cset.old_duplicates = cset.duplicates cset.duplicates = True # Player object's commandsets try: player_cmdset = caller.player.cmdset.current except AttributeError: player_cmdset = None cmdsets = [caller_cmdset] + [player_cmdset] + [channel_cmdset] + local_objects_cmdsets # weed out all non-found sets cmdsets = [cmdset for cmdset in cmdsets if cmdset] # sort cmdsets after reverse priority (highest prio are merged in last) cmdsets = sorted(cmdsets, key=lambda x: x.priority) if cmdsets: # Merge all command sets into one, beginning with the lowest-prio one cmdset = cmdsets.pop(0) for merging_cmdset in cmdsets: #print "<%s(%s,%s)> onto <%s(%s,%s)>" % (merging_cmdset.key, merging_cmdset.priority, merging_cmdset.mergetype, # cmdset.key, cmdset.priority, cmdset.mergetype) cmdset = merging_cmdset + cmdset else: cmdset = None for cset in (cset for cset in local_objects_cmdsets if cset): cset.duplicates = cset.old_duplicates return cmdset # Main command-handler function def cmdhandler(caller, raw_string, unloggedin=False, testing=False): """ This is the main function to handle any string sent to the engine. caller - calling object raw_string - the command string given on the command line unloggedin - if caller is an authenticated user or not testing - if we should actually execute the command or not. if True, the command instance will be returned instead. """ try: # catch bugs in cmdhandler itself try: # catch special-type commands if unloggedin: # not logged in, so it's just one cmdset we are interested in cmdset = import_cmdset(settings.CMDSET_UNLOGGEDIN, caller) else: # We are logged in, collect all relevant cmdsets and merge cmdset = get_and_merge_cmdsets(caller) #print cmdset if not cmdset: # this is bad and shouldn't happen. raise NoCmdSets raw_string = raw_string.strip() if not raw_string: # Empty input. Test for system command instead. syscmd = cmdset.get(CMD_NOINPUT) sysarg = "" raise ExecSystemCommand(syscmd, sysarg) # Parse the input string and match to available cmdset. # This also checks for permissions, so all commands in match # are commands the caller is allowed to call. matches = COMMAND_PARSER(raw_string, cmdset, caller) # Deal with matches if not matches: # No commands match our entered command syscmd = cmdset.get(CMD_NOMATCH) if syscmd: sysarg = raw_string else: sysarg = "Huh? (Type \"help\" for help)" raise ExecSystemCommand(syscmd, sysarg) if len(matches) > 1: # We have a multiple-match syscmd = cmdset.get(CMD_MULTIMATCH) sysarg = "There where multiple matches." if syscmd: syscmd.matches = matches else: sysarg = at_multimatch_cmd(caller, matches) raise ExecSystemCommand(syscmd, sysarg) # At this point, we have a unique command match. match = matches[0] cmdname, args, cmd = match[0], match[1], match[2] # Check if this is a Channel match. if hasattr(cmd, 'is_channel') and cmd.is_channel: # even if a user-defined syscmd is not defined, the # found cmd is already a system command in its own right. syscmd = cmdset.get(CMD_CHANNEL) if syscmd: # replace system command with custom version cmd = syscmd sysarg = "%s:%s" % (cmdname, args) raise ExecSystemCommand(cmd, sysarg) # A normal command. # Assign useful variables to the instance cmd.caller = caller cmd.cmdstring = cmdname cmd.args = args cmd.cmdset = cmdset if hasattr(cmd, 'obj') and hasattr(cmd.obj, 'scripts'): # cmd.obj are automatically made available. # we make sure to validate its scripts. cmd.obj.scripts.validate() if testing: # only return the command instance return cmd # pre-command hook cmd.at_pre_cmd() # Parse and execute cmd.parse() cmd.func() # post-command hook cmd.at_post_cmd() # Done! except ExecSystemCommand, exc: # Not a normal command: run a system command, if available, # or fall back to a return string. syscmd = exc.syscmd sysarg = exc.sysarg if syscmd: syscmd.caller = caller syscmd.cmdstring = syscmd.key syscmd.args = sysarg syscmd.cmdset = cmdset if hasattr(syscmd, 'obj') and hasattr(syscmd.obj, 'scripts'): # cmd.obj is automatically made available. # we make sure to validate its scripts. syscmd.obj.scripts.validate() if testing: # only return the command instance return syscmd # parse and run the command syscmd.parse() syscmd.func() elif sysarg: caller.msg(exc.sysarg) except NoCmdSets: # Critical error. string = "No command sets found! This is a sign of a critical bug.\n" string += "The error was logged.\n" string += "If logging out/in doesn't solve the problem, try to " string += "contact the server admin through some other means " string += "for assistance." caller.msg(string) logger.log_errmsg("No cmdsets found: %s" % caller) except Exception: # We should not end up here. If we do, it's a programming bug. string = "%s\nAbove traceback is from an untrapped error." string += " Please file a bug report." logger.log_trace(string) caller.msg(string % format_exc()) except Exception: # This catches exceptions in cmdhandler exceptions themselves string = "%s\nAbove traceback is from a Command handler bug." string += " Please contact an admin." logger.log_trace(string) caller.msg(string % format_exc()) #----------------------------------------------------- end cmdhandler