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

 1  """NDG XACML ElementTree Attribute Selector Reader   
 2   
 3  NERC DataGrid 
 4  """ 
 5  __author__ = "P J Kershaw" 
 6  __date__ = "18/03/10" 
 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: attributeselectorreader.py 7109 2010-06-28 12:54:57Z pjkersha $" 
12  from ndg.xacml.utils import str2Bool 
13  from ndg.xacml.core.attributeselector import AttributeSelector 
14  from ndg.xacml.parsers import XMLParseError 
15  from ndg.xacml.parsers.etree import QName 
16  from ndg.xacml.parsers.etree.expressionreader import ExpressionReader 
17   
18   
19 -class AttributeSelectorReader(ExpressionReader): 
20      '''ElementTree based parser for XACML Attribute Selector type 
21       
22      @cvar TYPE: XACML class type that this reader will read values into 
23      @type TYPE: abc.ABCMeta 
24      ''' 
25      TYPE = AttributeSelector 
26       
27 -    def _parseExtension(self, elem, attributeSelector): 
28          """Parse XML Attribute Selector element 
29           
30          @param elem: ElementTree XML element 
31          @type elem: xml.etree.Element 
32           
33          @param attributeSelector: attribute selector to be updated with parsed 
34          values 
35          @type attributeSelector: ndg.xacml.core.attributeSelector.AttributeSelector 
36           
37          @raise XMLParseError: error parsing attribute ID XML attribute 
38           
39          @return: updated attribute selector 
40          @rtype: ndg.xacml.core.attributeSelector.AttributeSelector 
41          """ 
42           
43          xacmlType = self.__class__.TYPE 
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          # Unpack *required* attributes from top-level element 
51          attributeValues = [] 
52          for attributeName in (xacmlType.REQUEST_CONTEXT_PATH_ATTRIB_NAME,): 
53              attributeValue = elem.attrib.get(attributeName) 
54              if attributeValue is None: 
55                  raise XMLParseError('No "%s" attribute found in "%s" element' % 
56                                      (attributeName,  
57                                       xacmlType.ELEMENT_LOCAL_NAME)) 
58                   
59              attributeValues.append(attributeValue) 
60                
61          attributeSelector.requestContextPath, = attributeValues 
62           
63          mustBePresent = elem.attrib.get(xacmlType.MUST_BE_PRESENT_ATTRIB_NAME) 
64          if mustBePresent is not None: 
65              attributeSelector.mustBePresent = str2Bool(mustBePresent) 
66            
67          return attributeSelector 
68