Mercurial > libervia-backend
view sat/tools/trigger.py @ 2834:6cd3549e8d67
we are in dev version again
author | Goffi <goffi@goffi.org> |
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date | Sat, 02 Mar 2019 18:43:09 +0100 |
parents | 003b8b4b56a7 |
children | ab2696e34d29 |
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#!/usr/bin/env python2 # -*- coding: utf-8 -*- # SAT: a jabber client # Copyright (C) 2009-2019 Jérôme Poisson (goffi@goffi.org) # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU Affero General Public License as published by # the Free Software Foundation, either version 3 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 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU Affero General Public License for more details. # You should have received a copy of the GNU Affero General Public License # along with this program. If not, see <http://www.gnu.org/licenses/>. """Misc usefull classes""" from sat.core.i18n import _ from sat.core.log import getLogger log = getLogger(__name__) class TriggerException(Exception): pass class SkipOtherTriggers(Exception): """ Exception to raise if normal behaviour must be followed instead of following triggers list """ pass class TriggerManager(object): """This class manage triggers: code which interact to change the behaviour of SàT""" try: # FIXME: to be removed when a better solution is found MIN_PRIORITY = float("-inf") MAX_PRIORITY = float("+inf") except: # XXX: Pyjamas will bug if you specify ValueError here # Pyjamas uses the JS Float class MIN_PRIORITY = Number.NEGATIVE_INFINITY MAX_PRIORITY = Number.POSITIVE_INFINITY def __init__(self): self.__triggers = {} def add(self, point_name, callback, priority=0): """Add a trigger to a point @param point_name: name of the point when the trigger should be run @param callback: method to call at the trigger point @param priority: callback will be called in priority order, biggest first """ if point_name not in self.__triggers: self.__triggers[point_name] = [] if priority != 0 and priority in [ trigger_tuple[0] for trigger_tuple in self.__triggers[point_name] ]: if priority in (self.MIN_PRIORITY, self.MAX_PRIORITY): log.warning(_(u"There is already a bound priority [%s]") % point_name) else: log.debug( _(u"There is already a trigger with the same priority [%s]") % point_name ) self.__triggers[point_name].append((priority, callback)) self.__triggers[point_name].sort( key=lambda trigger_tuple: trigger_tuple[0], reverse=True ) def remove(self, point_name, callback): """Remove a trigger from a point @param point_name: name of the point when the trigger should be run @param callback: method to remove, must exists in the trigger point """ for trigger_tuple in self.__triggers[point_name]: if trigger_tuple[1] == callback: self.__triggers[point_name].remove(trigger_tuple) return raise TriggerException("Trying to remove an unexisting trigger") def point(self, point_name, *args, **kwargs): """This put a trigger point All the triggers for that point will be run @param point_name: name of the trigger point @param *args: args to transmit to trigger @param *kwargs: kwargs to transmit to trigger if "triggers_no_cancel" is present, it will be popup out when set to True, this argument don't let triggers stop the workflow @return: True if the action must be continued, False else """ if point_name not in self.__triggers: return True can_cancel = not kwargs.pop('triggers_no_cancel', False) for priority, trigger in self.__triggers[point_name]: try: if not trigger(*args, **kwargs) and can_cancel: return False except SkipOtherTriggers: break return True def returnPoint(self, point_name, *args, **kwargs): """Like point but trigger must return (continue, return_value) All triggers for that point must return a tuple with 2 values: - continue, same as for point, if False action must be finished - return_value: value to return ONLY IF CONTINUE IS FALSE @param point_name: name of the trigger point @return: True if the action must be continued, False else """ if point_name not in self.__triggers: return True for priority, trigger in self.__triggers[point_name]: try: cont, ret_value = trigger(*args, **kwargs) if not cont: return False, ret_value except SkipOtherTriggers: break return True, None