src/mailman/pipeline/__init__.py

   1 # Copyright (C) 2008-2009 by the Free Software Foundation, Inc.
   2 #
   3 # This file is part of GNU Mailman.
   4 #
   5 # GNU Mailman is free software: you can redistribute it and/or modify it under
   6 # the terms of the GNU General Public License as published by the Free
   7 # Software Foundation, either version 3 of the License, or (at your option)
   8 # any later version.
   9 #
  10 # GNU Mailman is distributed in the hope that it will be useful, but WITHOUT
  11 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12 # FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13 # more details.
  14 #
  15 # You should have received a copy of the GNU General Public License along with
  16 # GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 """The built in set of pipeline handlers."""
  19
  20 from __future__ import absolute_import, unicode_literals
  21
  22 __metaclass__ = type
  23 __all__ = [
  24     'builtin_handlers',
  25     ]
  26
  27
  28 import os
  29 import sys
  30
  31 from mailman.interfaces.handler import IHandler
  32
  33
  34 \f
  35 def builtin_handlers():
  36     """Return the built-in handlers.
  37
  38     Rules are auto-discovered by searching for IHandler implementations in all
  39     importable modules in this subpackage.
  40     """
  41     # Find all rules found in all modules inside our package.
  42     import mailman.pipeline
  43     here = os.path.dirname(mailman.pipeline.__file__)
  44     for filename in os.listdir(here):
  45         basename, extension = os.path.splitext(filename)
  46         if extension <> '.py':
  47             continue
  48         module_name = 'mailman.pipeline.' + basename
  49         __import__(module_name, fromlist='*')
  50         module = sys.modules[module_name]
  51         for name in getattr(module, '__all__', ()):
  52             handler = getattr(module, name)
  53             if IHandler.implementedBy(handler):
  54                 yield handler