twisted/web/google.py

   1 # Copyright (c) Twisted Matrix Laboratories.
   2 # See LICENSE for details.
   3
   4 #
   5 """\"I'm Feeling Lucky\" with U{Google<http://google.com>}.
   6 """
   7 import urllib
   8 from twisted.internet import protocol, reactor, defer
   9 from twisted.web import http
  10
  11 class GoogleChecker(http.HTTPClient):
  12
  13     def connectionMade(self):
  14         self.sendCommand('GET', self.factory.url)
  15         self.sendHeader('Host', self.factory.host)
  16         self.sendHeader('User-Agent', self.factory.agent)
  17         self.endHeaders()
  18
  19     def handleHeader(self, key, value):
  20         key = key.lower()
  21         if key == 'location':
  22             self.factory.gotLocation(value)
  23
  24     def handleStatus(self, version, status, message):
  25         if status != '302':
  26             self.factory.noLocation(ValueError("bad status"))
  27
  28     def handleEndHeaders(self):
  29         self.factory.noLocation(ValueError("no location"))
  30
  31     def handleResponsePart(self, part):
  32         pass
  33
  34     def handleResponseEnd(self):
  35         pass
  36
  37     def connectionLost(self, reason):
  38         self.factory.noLocation(reason)
  39
  40
  41 class GoogleCheckerFactory(protocol.ClientFactory):
  42
  43     protocol = GoogleChecker
  44
  45     def __init__(self, words):
  46         self.url = ('/search?q=%s&btnI=%s' %
  47                     (urllib.quote_plus(' '.join(words)),
  48                      urllib.quote_plus("I'm Feeling Lucky")))
  49         self.agent="Twisted/GoogleChecker"
  50         self.host = "www.google.com"
  51         self.deferred = defer.Deferred()
  52
  53     def clientConnectionFailed(self, _, reason):
  54         self.noLocation(reason)
  55
  56     def gotLocation(self, location):
  57         if self.deferred:
  58             self.deferred.callback(location)
  59             self.deferred = None
  60
  61     def noLocation(self, error):
  62         if self.deferred:
  63             self.deferred.errback(error)
  64             self.deferred = None
  65
  66
  67 def checkGoogle(words):
  68     """Check google for a match.
  69
  70     @returns: a Deferred which will callback with a URL or errback with a
  71         Failure.
  72     """
  73     factory = GoogleCheckerFactory(words)
  74     reactor.connectTCP('www.google.com', 80, factory)
  75     return factory.deferred