pli/misc/acl.py

   1 #=======================================================================
   2
   3 __version__ = '''0.0.12'''
   4 __sub_version__ = '''20050110052820'''
   5 __copyright__ = '''(c) Alex A. Naanou 2003'''
   6
   7
   8 #-----------------------------------------------------------------------
   9
  10 __doc__ = '''
  11 General ACL Protocol:
  12         objects that want to use this protocol may define the following
  13         attributes:
  14
  15         __public__                      : if True will render the object accessible;
  16                                                   if False will prevent access to the object;
  17                                                   (default: True)
  18         __public_attrs__        : will define a list of attributes that are to be visible.
  19         __private_attrs__       : will define a list of attributes that are not to be visible.
  20         __writable_attrs__      : will define a list of attributes that are writable.
  21         __readonly_attrs__      : will define a list of attributes that are not writable.
  22
  23         [not done]
  24         __global_methods_allowed__
  25                                                 : will define the allowed global methods for the current object.
  26                                                   if True allow all...
  27         __global_methods_disallowed__
  28                                                 : will define the disallowed global methods for the current object.
  29                                                   if True disallow all... (takes priority over __global_methods_allowed__)
  30
  31         TODO do global method acl for attrs...
  32
  33         __acl__                         : ... (not yet done...)
  34                                                   the format is as follows:
  35                                                   { <obj_id> : {<prop>:<val>[, <prop>:<val>[...]]}[, ...]}
  36                                                                 <obj_id>        : this can be an object or a class (name or ref).
  37                                                                 <prop>          : this can be any of the above (except __acl__)
  38 '''
  39 #
  40 # ACL:
  41 #       qualifires:
  42 #               <qualifier-name>
  43 #       rules:
  44 #               <qualifier-name> : <action>[, <action>[...]]
  45 #               <action> : <qualifier-name>[, <qualifier-name>[...]]
  46 #       actions:
  47 #               default:
  48 #                       read
  49 #                       write
  50 #                       execute
  51 #               custon:
  52 #                       <action-name> : <method-name>
  53 #
  54 # methods: (aspects)
  55 #       setacl(method, <acl>)
  56 #
  57 #
  58 #
  59
  60
  61 # TODO rename all attrs to __acl_<name>__ (???)
  62
  63
  64 #-----------------------------------------------------------------------
  65
  66 import __builtin__
  67 _hasattr = hasattr
  68 _getattr = getattr
  69 _setattr = setattr
  70 ##_delattr = __builtin__.delattr
  71 import sys
  72
  73
  74 #-----------------------------------------------------------------------
  75 # TODO process __acl__
  76 #-----------------------------------------------------------isvisible---
  77 def isvisible(obj, uid=None):
  78         '''
  79         '''
  80         if _hasattr(obj, '__visible__') and not obj.__visible__:
  81                 return False
  82         return True
  83
  84
  85 #--------------------------------------------------------isaccessible---
  86 def isaccessible(obj, uid=None):
  87         '''
  88         '''
  89         if _hasattr(obj, '__public__') and not obj.__public__:
  90                 return False
  91         return True
  92
  93
  94 #-----------------------------------------------isglobalmethodallowed---
  95 def isglobalmethodallowed(obj, meth, uid=None):
  96         '''
  97         '''
  98         if isaccessible(obj) and \
  99                 (not _hasattr(obj, '__global_methods_disallowed__') or meth not in obj.__global_methods_disallowed__) and \
 100                 (not _hasattr(obj, '__global_methods_allowed__') or meth in obj.__global_methods_allowed__):
 101                         return True
 102         return False
 103
 104
 105 #-------------------------------------------------------------hasattr---
 106 def hasattr(obj, name, uid=None):
 107         '''
 108         '''
 109         if isaccessible(obj) and \
 110                         (not _hasattr(obj, '__private_attrs__') or name not in obj.__private_attrs__) and\
 111                         (not _hasattr(obj, '__public_attrs__') or name in obj.__public_attrs__):
 112                 if not _hasattr(obj, name):
 113                         return False
 114                 o_obj = _getattr(obj, name)
 115                 if isaccessible(o_obj):
 116                         return True
 117         return False
 118
 119
 120 #-------------------------------------------------------------getattr---
 121 def getattr(obj, name, uid=None):
 122         '''
 123         '''
 124         if isaccessible(obj) and \
 125                         (not _hasattr(obj, '__private_attrs__') or name not in obj.__private_attrs__) and\
 126                         (not _hasattr(obj, '__public_attrs__') or name in obj.__public_attrs__):
 127                 o_obj = _getattr(obj, name)
 128                 if isaccessible(o_obj):
 129                         return o_obj
 130         raise AttributeError, '"%s" object has no attribute "%s".' % (obj, name)
 131
 132
 133 #----------------------------------------------------------iswritable---
 134 def iswritable(obj, name, uid=None):
 135         '''
 136         '''
 137         if isaccessible(obj) and \
 138                         (not _hasattr(obj, '__private_attrs__') or name not in obj.__private_attrs__) and\
 139                         (not _hasattr(obj, '__public_attrs__') or name in obj.__public_attrs__) and\
 140                         (not _hasattr(obj, '__writable_attrs__') or name in obj.__writable_attrs__) and\
 141                         (not _hasattr(obj, '__readonly_attrs__') or name not in obj.__readonly_attrs__):
 142                 try:
 143                         o_obj = _getattr(obj, name)
 144                         if isaccessible(o_obj):
 145                                 return True
 146                 except AttributeError:
 147                         return True
 148         return False
 149
 150
 151 #-------------------------------------------------------------setattr---
 152 def setattr(obj, name, val, uid=None):
 153         '''
 154         '''
 155         if isaccessible(obj) and \
 156                         (not _hasattr(obj, '__private_attrs__') or name not in obj.__private_attrs__) and\
 157                         (not _hasattr(obj, '__public_attrs__') or name in obj.__public_attrs__) and\
 158                         (not _hasattr(obj, '__writable_attrs__') or name in obj.__writable_attrs__) and\
 159                         (not _hasattr(obj, '__readonly_attrs__') or name not in obj.__readonly_attrs__):
 160                 return _setattr(obj, name, val)
 161         raise AttributeError, 'can\'t write attribute "%s" of object "%s".' % (name, obj)
 162
 163
 164 ###-------------------------------------------------------------delattr---
 165 ##def delattr(obj, name, uid=None):
 166 ##      '''
 167 ##      '''
 168
 169
 170 ###--------------------------------------------inheritclasssecuritylist---
 171 ##def inheritclasssecuritylist(prop):
 172 ##      '''
 173 ##      this will return a tuple which is the union of the security option
 174 ##      given, set in the classes bases.
 175 ##      '''
 176 ##      cls = sys._getframe(1)
 177 ##      res = []
 178 ##      for c in cls.__bases__:
 179 ##              if _hasattr(c, prop):
 180 ##                      res += _getattr(c, prop)
 181 ##      return tuple(dict([(i, None) for i in res]).keys())
 182
 183
 184 #=======================================================================
 185 #                                             vim:set ts=4 sw=4 nowrap: