Source Code for Module openid.yadis.xrires

  1  # -*- test-case-name: openid.test.test_xrires -*- 
  2  """XRI resolution. 
  3  """ 
  4   
  5  from urllib import urlencode 
  6  from openid import fetchers 
  7  from openid.yadis import etxrd 
  8  from openid.yadis.xri import toURINormal 
  9  from openid.yadis.services import iterServices 
 10   
 11  DEFAULT_PROXY = 'http://proxy.xri.net/' 
 12   
 13 -class ProxyResolver(object): 
 14      """Python interface to a remote XRI proxy resolver. 
 15      """ 
 16 -    def __init__(self, proxy_url=DEFAULT_PROXY): 
 17          self.proxy_url = proxy_url 
 18   
 19   
 20 -    def queryURL(self, xri, service_type=None): 
 21          """Build a URL to query the proxy resolver. 
 22   
 23          @param xri: An XRI to resolve. 
 24          @type xri: unicode 
 25   
 26          @param service_type: The service type to resolve, if you desire 
 27              service endpoint selection.  A service type is a URI. 
 28          @type service_type: str 
 29   
 30          @returns: a URL 
 31          @returntype: str 
 32          """ 
 33          # Trim off the xri:// prefix.  The proxy resolver didn't accept it 
 34          # when this code was written, but that may (or may not) change for 
 35          # XRI Resolution 2.0 Working Draft 11. 
 36          qxri = toURINormal(xri)[6:] 
 37          hxri = self.proxy_url + qxri 
 38          args = { 
 39              # XXX: If the proxy resolver will ensure that it doesn't return 
 40              # bogus CanonicalIDs (as per Steve's message of 15 Aug 2006 
 41              # 11:13:42), then we could ask for application/xrd+xml instead, 
 42              # which would give us a bit less to process. 
 43              '_xrd_r': 'application/xrds+xml', 
 44              } 
 45          if service_type: 
 46              args['_xrd_t'] = service_type 
 47          else: 
 48              # Don't perform service endpoint selection. 
 49              args['_xrd_r'] += ';sep=false' 
 50          query = _appendArgs(hxri, args) 
 51          return query 
 52   
 53   
 54 -    def query(self, xri, service_types): 
 55          """Resolve some services for an XRI. 
 56   
 57          Note: I don't implement any service endpoint selection beyond what 
 58          the resolver I'm querying does, so the Services I return may well 
 59          include Services that were not of the types you asked for. 
 60   
 61          May raise fetchers.HTTPFetchingError or L{etxrd.XRDSError} if 
 62          the fetching or parsing don't go so well. 
 63   
 64          @param xri: An XRI to resolve. 
 65          @type xri: unicode 
 66   
 67          @param service_types: A list of services types to query for.  Service 
 68              types are URIs. 
 69          @type service_types: list of str 
 70   
 71          @returns: tuple of (CanonicalID, Service elements) 
 72          @returntype: (unicode, list of C{ElementTree.Element}s) 
 73          """ 
 74          # FIXME: No test coverage! 
 75          services = [] 
 76          # Make a seperate request to the proxy resolver for each service 
 77          # type, as, if it is following Refs, it could return a different 
 78          # XRDS for each. 
 79   
 80          canonicalID = None 
 81   
 82          for service_type in service_types: 
 83              url = self.queryURL(xri, service_type) 
 84              response = fetchers.fetch(url) 
 85              if response.status not in (200, 206): 
 86                  # XXX: sucks to fail silently. 
 87                  # print "response not OK:", response 
 88                  continue 
 89              et = etxrd.parseXRDS(response.body) 
 90              canonicalID = etxrd.getCanonicalID(xri, et) 
 91              some_services = list(iterServices(et)) 
 92              services.extend(some_services) 
 93          # TODO: 
 94          #  * If we do get hits for multiple service_types, we're almost 
 95          #    certainly going to have duplicated service entries and 
 96          #    broken priority ordering. 
 97          return canonicalID, services 
 98   
 99   
100 -def _appendArgs(url, args): 
101      """Append some arguments to an HTTP query. 
102      """ 
103      # to be merged with oidutil.appendArgs when we combine the projects. 
104      if hasattr(args, 'items'): 
105          args = args.items() 
106          args.sort() 
107   
108      if len(args) == 0: 
109          return url 
110   
111      # According to XRI Resolution section "QXRI query parameters": 
112      # 
113      # """If the original QXRI had a null query component (only a leading 
114      #    question mark), or a query component consisting of only question 
115      #    marks, one additional leading question mark MUST be added when 
116      #    adding any XRI resolution parameters.""" 
117   
118      if '?' in url.rstrip('?'): 
119          sep = '&' 
120      else: 
121          sep = '?' 
122   
123      return '%s%s%s' % (url, sep, urlencode(args)) 
124