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

 1  """NDG XACML ElementTree based Generic Target Child Element reader - for 
 2  Reosurce, Subject, Action and Environment 
 3   
 4  NERC DataGrid 
 5  """ 
 6  __author__ = "P J Kershaw" 
 7  __date__ = "18/03/10" 
 8  __copyright__ = "(C) 2010 Science and Technology Facilities Council" 
 9  __contact__ = "Philip.Kershaw@stfc.ac.uk" 
10  __license__ = "BSD - see LICENSE file in top-level directory" 
11  __contact__ = "Philip.Kershaw@stfc.ac.uk" 
12  __revision__ = "$Id: targetchildreader.py 8028 2012-02-27 14:38:01Z rwilkinson $" 
13  from ndg.xacml.parsers import XMLParseError 
14  from ndg.xacml.parsers.etree import QName, getElementChildren 
15  from ndg.xacml.parsers.etree.reader import ETreeAbstractReader 
16  from ndg.xacml.parsers.etree.factory import ReaderFactory 
17   
18   
19 -class TargetChildReader(ETreeAbstractReader): 
20      '''ElementTree based XACML generic target child element parser 
21      @cvar TYPE: XACML type to instantiate from parsed object 
22      @type TYPE: type 
23      ''' 
24   
25 -    def __call__(self, obj, common): 
26          """Parse target child element object 
27           
28          @param obj: input object to parse 
29          @type obj: ElementTree Element, or stream object 
30          @return: new XACML expression instance 
31          @rtype: ndg.xacml.core.TargetChildBase derived type  
32          @raise XMLParseError: error reading element                
33          """ 
34          elem = super(TargetChildReader, self)._parse(obj) 
35           
36          xacmlType = self.__class__.TYPE 
37          targetChild = xacmlType() 
38           
39          localName = QName.getLocalPart(elem.tag) 
40          if localName != xacmlType.ELEMENT_LOCAL_NAME: 
41              raise XMLParseError("No \"%s\" element found" %  
42                                  xacmlType.ELEMENT_LOCAL_NAME) 
43               
44          # Parse match elements 
45          for childElem in getElementChildren(elem): 
46              localName = QName.getLocalPart(childElem.tag) 
47               
48              if localName == xacmlType.MATCH_TYPE.ELEMENT_LOCAL_NAME: 
49                  # Get reader for the match type 
50                  matchReader = ReaderFactory.getReader(xacmlType.MATCH_TYPE) 
51                  targetChild.matches.append(matchReader.parse(childElem, common)) 
52               
53              else: 
54                  raise XMLParseError("XACML %r child element name %r not " 
55                                      "recognised" % (xacmlType.ELEMENT_LOCAL_NAME, 
56                                                      localName)) 
57                          
58          return targetChild 
59