Source Code for Module ndg.xacml.parsers.etree.targetreader

 1  """NDG XACML ElementTree based Target Element reader  
 2   
 3  NERC DataGrid 
 4  """ 
 5  __author__ = "P J Kershaw" 
 6  __date__ = "16/03/10" 
 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: targetreader.py 8028 2012-02-27 14:38:01Z rwilkinson $" 
12  from ndg.xacml.core.target import Target 
13  from ndg.xacml.core.subject import Subject 
14  from ndg.xacml.core.resource import Resource 
15  from ndg.xacml.core.action import Action 
16  from ndg.xacml.core.environment import Environment 
17  from ndg.xacml.parsers import XMLParseError 
18  from ndg.xacml.parsers.etree import QName, getElementChildren 
19  from ndg.xacml.parsers.etree.reader import ETreeAbstractReader 
20  from ndg.xacml.parsers.etree.factory import ReaderFactory 
21   
22   
23 -class TargetReader(ETreeAbstractReader): 
24      """ElementTree based parser for XACML Target elements 
25       
26      @cvar TYPE: XACML type to instantiate from parsed object 
27      @type TYPE: type 
28      """ 
29      TYPE = Target 
30       
31 -    def __call__(self, obj, common): 
32          """Parse Target object 
33           
34          @param obj: input object to parse 
35          @type obj: ElementTree Element, or stream object 
36          @return: new XACML expression instance 
37          @rtype: ndg.xacml.core.target.Target derived type  
38          @raise XMLParseError: error reading element                
39          """ 
40          elem = super(TargetReader, self)._parse(obj) 
41           
42          xacmlType = TargetReader.TYPE 
43          target = xacmlType() 
44           
45          localName = QName.getLocalPart(elem.tag) 
46          if localName != xacmlType.ELEMENT_LOCAL_NAME: 
47              raise XMLParseError('No "%s" element found' %  
48                                  xacmlType.ELEMENT_LOCAL_NAME) 
49           
50          # Parse sub-elements 
51          for childElem in getElementChildren(elem): 
52              localName = QName.getLocalPart(childElem.tag) 
53               
54              if localName == xacmlType.SUBJECTS_ELEMENT_LOCAL_NAME: 
55                  for subjElem in getElementChildren(childElem): 
56                      SubjectReader = ReaderFactory.getReader(Subject) 
57                      target.subjects.append(SubjectReader.parse(subjElem, 
58                                                                 common)) 
59                                   
60              elif localName == xacmlType.RESOURCES_ELEMENT_LOCAL_NAME: 
61                  for resourceElem in getElementChildren(childElem): 
62                      ResourceReader = ReaderFactory.getReader(Resource) 
63                      target.resources.append(ResourceReader.parse(resourceElem, 
64                                                                   common)) 
65                   
66              elif localName == xacmlType.ACTIONS_ELEMENT_LOCAL_NAME: 
67                  for targetElem in getElementChildren(childElem): 
68                      ActionReader = ReaderFactory.getReader(Action) 
69                      target.actions.append(ActionReader.parse(targetElem, 
70                                                               common)) 
71                   
72              elif localName == xacmlType.ENVIRONMENTS_ELEMENT_LOCAL_NAME: 
73                  for environElem in getElementChildren(childElem): 
74                      EnvironmentReader = ReaderFactory.getReader(Environment) 
75                      target.environments.append(EnvironmentReader.parse( 
76                                                          environElem, common)) 
77              else: 
78                  raise XMLParseError("XACML Target child element name %r not " 
79                                      "recognised" % localName) 
80                   
81          return target 
82