paula.properties/src/paula/properties/subscribers.py

   1 # Copyright (c) 2008 by Florian Friesdorf
   2 #
   3 # GNU Affero General Public License (AGPL)
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU Affero General Public License as
   7 # published by the Free Software Foundation; either version 3 of the
   8 # License, or (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13 # GNU Affero General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU Affero General Public
  16 # License along with this program.  If not, see
  17 # <http://www.gnu.org/licenses/>.
  18 """
  19 """
  20 __author__ = "Florian Friesdorf <flo@chaoflow.net>"
  21 __docformat__ = "plaintext"
  22
  23 from zope.app.authentication.interfaces import IPrincipalCreated
  24
  25 from zope.component import adapter, queryUtility
  26 from zope.interface import alsoProvides
  27
  28 from paula.properties.interfaces import IPropertyInterface
  29 from paula.properties.interfaces import IPropertyProvider
  30 from paula.properties.interfaces import IPropertyProviders
  31
  32 def _copy_attributes_from_ppu( principal, pps):
  33     """
  34     A mockup principal
  35
  36         >>> p = Mock(id='1')
  37
  38     A mockup property provider
  39
  40         >>> class IA(Interface):
  41         ...     a1 = Attribute(u"a1")
  42         ...     a2 = Attribute(u"a2")
  43         >>> alsoProvides(IA, IPropertyInterface)
  44
  45         >>> class IB(Interface):
  46         ...     b = Attribute(u"b")
  47         >>> alsoProvides(IB, IPropertyInterface)
  48
  49         >>> class IC(Interface):
  50         ...     c = Attribute(u"c")
  51
  52         >>> pp1 = Mock(
  53         ...         a1=1,
  54         ...         a2=2,
  55         ...         b=3,
  56         ...         c='not copied',
  57         ...         alsoProvides=(IA,IB),
  58         ...         )
  59
  60     And another one
  61
  62         >>> class ID(Interface):
  63         ...     d = Attribute(u"d")
  64         >>> alsoProvides(ID, IPropertyInterface)
  65
  66         >>> pp2 = Mock(d=4, alsoProvides=(ID,))
  67
  68     A list of property provider utilities
  69
  70         >>> pps = [pp1, pp2]
  71
  72     Call and check which attributes made it
  73
  74         >>> _copy_attributes_from_ppu(p, pps)
  75         >>> IA.providedBy(p)
  76         True
  77         >>> IB.providedBy(p)
  78         True
  79         >>> IC.providedBy(p)
  80         False
  81         >>> ID.providedBy(p)
  82         True
  83         >>> p.a1
  84         1
  85         >>> p.a2
  86         2
  87         >>> p.b
  88         3
  89         >>> getattr(p, 'c', 'foo')
  90         'foo'
  91         >>> p.d
  92         4
  93     """
  94     for pp in pps:
  95         schemas = list(pp.__provides__)
  96         for schema in schemas:
  97             # only use interfaces that defined properties
  98             if not IPropertyInterface.providedBy(schema):
  99                 continue
 100             # iterate over schema fields and copy values
 101             # also see comment below, dynamic lookup would be great
 102             for name in list(schema):
 103                 value = getattr(schema(pp), name)
 104                 setattr(principal, name, value)
 105             alsoProvides(principal, schema)
 106
 107
 108             #XXX: this is not working, as property object most probably
 109             #     do magic inside of __getattr__ and rely on classes to
 110             #     interpret them correctly.
 111             #     Another way would be to monkey-patch user's
 112             #     __getattr__...
 113             #     For now we leave it static, i.e. the values are taken
 114             #     only once and are not dynamically updated. Not sure,
 115             #     whether it is useful anyway, as I don't know how long
 116             #     Principals exist at all.
 117             #prop = property( lambda self: getattr(principal, name))
 118             #setattr(user, name, prop)
 119
 120
 121 @adapter(IPrincipalCreated)
 122 def setPropertiesForPrincipal(event):
 123     """Put properties onto the principal
 124
 125     The properties are directly stored as attributes. Magic happens in
 126     _copy_attributes_from_ppu, here we just get the utility and are tested
 127     in README.txt
 128     """
 129     principal = event.principal
 130     # we search for a property provider utility in the context of the auth
 131     # plugin that authenticated the principal, if there is none, we do
 132     # nothing
 133     ppu = queryUtility(
 134             IPropertyProviders,
 135     #        context=getSite(),
 136             )
 137     # XXX: for some reason a ppu is False
 138     if ppu is not None and principal.id in ppu:
 139         pps = ppu[principal.id]
 140         _copy_attributes_from_ppu( principal, pps)