Source Code for Module ndg.xacml.core.context.request

  1  """NDG XACML module for Request type  
  2   
  3  NERC DataGrid 
  4  """ 
  5  __author__ = "P J Kershaw" 
  6  __date__ = "23/03/10" 
  7  __copyright__ = "(C) 2010 Science and Technology Facilities Council" 
  8  __contact__ = "Philip.Kershaw@stfc.ac.uk" 
  9  __license__ = "BSD - see LICENSE file in top-level directory" 
 10  __contact__ = "Philip.Kershaw@stfc.ac.uk" 
 11  __revision__ = "$Id: request.py 8010 2012-01-30 16:24:06Z rwilkinson $" 
 12  import logging 
 13  log = logging.getLogger(__name__) 
 14   
 15  from ndg.xacml.utils import TypedList 
 16  from ndg.xacml.core.context import XacmlContextBase 
 17  from ndg.xacml.core.context.subject import Subject 
 18  from ndg.xacml.core.context.resource import Resource 
 19  from ndg.xacml.core.context.action import Action 
 20  from ndg.xacml.core.context.environment import Environment 
 21  from ndg.xacml.core.context.handlerinterface import CtxHandlerInterface 
 22  from ndg.xacml.utils.xpath_selector import XPathSelectorInterface 
 23   
 24   
 25 -class Request(XacmlContextBase): 
 26      """XACML Request class 
 27       
 28      @cvar ELEMENT_LOCAL_NAME: XML local element name, derived classes should 
 29      set 
 30      @type ELEMENT_LOCAL_NAME: string 
 31       
 32      @ivar __subjects: list of subjects corresponding to this request 
 33      @type __subjects: ndg.xacml.utils.TypedList 
 34      @ivar __resources: list of resources corresponding to this request 
 35      @type __subjects: ndg.xacml.utils.TypedList 
 36      @ivar __action: action for this request  
 37      @type __action: None / ndg.xacml.core.context.action.Action 
 38      @ivar __environment: environment associated with this request  
 39      @type __environment: None / ndg.xacml.core.context.environment.Environment 
 40       
 41      @ivar ctxHandler: reference to context handler to enable the PDP to 
 42      query for additional attributes.  The Context Handler itself queries a 
 43      Policy Information Point.  This handler setting may be omitted.  If so, 
 44      the PDP will rely entirely on the input request context for making  
 45      access control decisions 
 46      @type ctxHandler: ndg.xacml.core.context.handler.CtxHandlerInterface /  
 47      None 
 48      """ 
 49      __slots__ = ( 
 50          '__subjects',  
 51          '__resources',  
 52          '__action',  
 53          '__environment', 
 54          '__ctxHandler', 
 55          '__attributeSelector', 
 56      ) 
 57      ELEMENT_LOCAL_NAME = 'Request' 
 58       
 59 -    def __init__(self): 
 60          super(Request, self).__init__() 
 61           
 62          self.__subjects = TypedList(Subject) 
 63          self.__resources = TypedList(Resource) 
 64          self.__action = None 
 65          self.__environment = None 
 66           
 67          self.__ctxHandler = None 
 68          self.__attributeSelector = None 
 69                       
 70      @property 
 71 -    def subjects(self): 
 72          """Get Request subjects 
 73          @return: list of subjects 
 74          @rtype: ndg.xacml.utils.TypedList 
 75          """ 
 76          return self.__subjects 
 77           
 78      @property 
 79 -    def resources(self): 
 80          """Get Request resources 
 81          @return: list of resources 
 82          @rtype: ndg.xacml.utils.TypedList 
 83          """ 
 84          return self.__resources 
 85                                       
 86      @property 
 87 -    def action(self): 
 88          """Get Request action 
 89          @return: action type 
 90          @rtype: None / ndg.xacml.core.context.action.Action 
 91          """ 
 92          return self.__action 
 93       
 94      @action.setter 
 95 -    def action(self, value): 
 96          """Set Request action 
 97          @param value: action type 
 98          @type value: ndg.xacml.core.context.action.Action 
 99          """ 
100          if not isinstance(value, Action): 
101              raise TypeError('Expecting %r type for request "action" ' 
102                              'attribute; got %r' % (Action, type(value))) 
103               
104          self.__action = value 
105                                       
106      @property 
107 -    def environment(self): 
108          """Get Request environment 
109          @return: environment settings 
110          @rtype: None / ndg.xacml.core.context.environment.Environment 
111          """ 
112          return self.__environment 
113       
114      @environment.setter 
115 -    def environment(self, value): 
116          """Set Request environment 
117          @param value: environment settings 
118          @type value: ndg.xacml.core.context.environment.Environment 
119          """ 
120          if not isinstance(value, Environment): 
121              raise TypeError('Expecting %r type for request "environment" ' 
122                              'attribute; got %r' % (Environment, type(value))) 
123                
124          self.__environment = value    
125   
126      @property 
127 -    def ctxHandler(self): 
128          """Get Context handler used by evaluate method to query the PIP for 
129          additional attribute values 
130          @return: context handler 
131          @rtype: None / ndg.xacml.core.context.handler.CtxHandlerInterface  
132          derived type   
133          """ 
134          return self.__ctxHandler 
135   
136      @ctxHandler.setter 
137 -    def ctxHandler(self, value): 
138          """Set Context handler used by evaluate method to query the PIP for 
139          additional attribute values 
140          @param value: context handler 
141          @type value: ndg.xacml.core.context.handler.CtxHandlerInterface  
142          derived type   
143          """ 
144          if not isinstance(value, CtxHandlerInterface): 
145              raise TypeError('Expecting %r type for "ctxHandler" attribute; got ' 
146                              '%r' % (CtxHandlerInterface, type(value))) 
147               
148          self.__ctxHandler = value 
149   
150      @property 
151 -    def attributeSelector(self): 
152          """Get attribute selector used to make XPath selections on request 
153          @return: attribute selector 
154          @rtype: None / ndg.xacml.utils.xpath_selector.XpathSelectorInterface 
155          derived type 
156          """ 
157          return self.__attributeSelector 
158   
159      @attributeSelector.setter 
160 -    def attributeSelector(self, value): 
161          """Set attribute selector used to make XPath selections on request 
162          @param value: attribute selector 
163          @type value: ndg.xacml.utils.xpath_selector.XpathSelectorInterface 
164          derived type 
165          """ 
166          if not isinstance(value, XPathSelectorInterface): 
167              raise TypeError('Expecting %r type for "attributeSelector" ' 
168                              'attribute; got %r' % 
169                              (XPathSelectorInterface, type(value))) 
170               
171          self.__attributeSelector = value 
172   
173 -    def __getstate__(self): 
174          '''Enable pickling 
175           
176          @return: object's attribute dictionary 
177          @rtype: dict 
178          ''' 
179          _dict = super(Request, self).__getstate__() 
180          for attrName in Request.__slots__: 
181              # Ugly hack to allow for derived classes setting private member 
182              # variables 
183              if attrName.startswith('__'): 
184                  attrName = "_Request" + attrName 
185                   
186              _dict[attrName] = getattr(self, attrName) 
187               
188          return _dict 
189