Source Code for Module ndg.xacml.core.functions.v1.not

 1  """NDG XACML one and only functions module 
 2   
 3  NERC DataGrid 
 4  """ 
 5  __author__ = "Prashant Kediyal" 
 6  __date__ = "03/01/12" 
 7  __copyright__ = "" 
 8  __license__ = "BSD - see LICENSE file in top-level directory" 
 9  __contact__ = "pkediyal@gmail.com" 
10  __revision__ = '$Id$' 
11  from ndg.xacml.core.functions import (AbstractFunction,  
12                                        FunctionClassFactoryInterface) 
13  from ndg.xacml.core.context.exceptions import XacmlContextTypeError 
14   
15   
16 -class Not(AbstractFunction): 
17      """Base class for XACML <type>-and functions 
18       
19      @cvar FUNCTION_NS: namespace for this function 
20      @type FUNCTION_NS: string 
21      @cvar ATTRIBUTE_TYPE: type for arguments 
22      @type ATTRIBUTE_TYPE: str 
23      """ 
24      FUNCTION_NS = AbstractFunction.V1_0_FUNCTION_NS + 'not' 
25      ATTRIBUTE_TYPE = bool 
26   
27 -    def evaluate(self, attribute=None): 
28          """perform not function on the element 
29   
30          access_control-xacml-2.0-core-spec-os, Fe 2005 - A.3.5 Logical functions 
31   
32          @param attribute: elements to be NOT'ed 
33          @type attribute: bool 
34   
35          @return: result of NOT operation on the inputs 
36          @rtype: bool 
37   
38          """ 
39          if type(attribute) != self.__class__.ATTRIBUTE_TYPE: 
40              raise XacmlContextTypeError('Expecting %r type for attribute; ' 
41                                          'got %r' % 
42                                          (self.__class__.ATTRIBUTE_TYPE, 
43                                           type(attribute))) 
44   
45          if attribute is None: 
46              response = False 
47          else: 
48              response = not attribute 
49   
50          return response 
51   
52   
53 -class FunctionClassFactory(FunctionClassFactoryInterface): 
54      """Class Factory for not XACML function class 
55       
56      @cvar FUNCTION_NS: URN for not function 
57      @type FUNCTION_NS: string 
58      """ 
59      FUNCTION_NS = 'urn:oasis:names:tc:xacml:1.0:function:not' 
60       
61 -    def __call__(self, identifier): 
62          '''Create class for the Not XACML function identifier 
63           
64          @param identifier: XACML and function identifier 
65          @type identifier: basestring 
66          @return: and function class or None if identifier doesn't match 
67          @rtype: ndg.xacml.core.functions.v1.not.Not / NoneType 
68          ''' 
69          if identifier == Not.FUNCTION_NS: 
70              return Not 
71          else: 
72              return None 
73