sfatables/xmlextension.py

   1 # Matches and targets are specified using XML files.
   2 # They provide the following information:
   3 #   - The context required by the match
   4 #   - The processor that actually implements the match or target
   5 #   - The parameters that the processor needs to evaluate the context
   6
   7 import libxml2
   8 from sfatables.globals import *
   9
  10 class Xmlextension:
  11     context = ""
  12     processor = ""
  13     operand = "VALUE"
  14     arguments = []
  15
  16     def __init__(self, dir, component_name):
  17         filename = dir+"/"+component_name+".xml"
  18         import pdb
  19         pdb.set_trace()
  20         self.xmldoc = libxml2.parseFile(filename)
  21
  22         # TODO: Check xmldoc against a schema
  23         p = self.xmldoc.xpathNewContext()
  24
  25         # <context select="..."/>
  26         # <rule><argument param="..."/></rule>
  27         # <processor name="..."/>
  28
  29         context = p.xpathEval('//context/@select')
  30         self.context = context[0].content
  31
  32         processor = p.xpathEval('//processor/@filename')
  33         self.context = processor[0].content
  34
  35         name = p.xpathEval('//rule/argument/name')
  36         help = p.xpathEval('//rule/argument/help')
  37         target = p.xpathEval('//rule/argument/operand')
  38
  39         self.arguments = map(lambda (name,help,target):{'name':name.content,'help':help.content,'target':target.content}, zip(name,help,target))
  40
  41         p.xpathFreeContext()
  42         self.xmldoc.freeDoc()
  43
  44         return
  45