guestbook/guestbook8_logging.py

   1 import cgi
   2 import os
   3 import pickle
   4 import logging
   5
   6 from google.appengine.api import users
   7 from google.appengine.ext import webapp
   8 from google.appengine.ext.webapp.util import run_wsgi_app
   9 from google.appengine.ext import db
  10 from google.appengine.ext.webapp import template
  11 from google.appengine.api import memcache
  12
  13 MEMCACHE_GREETINGS = 'greetings'
  14
  15 class Greeting(db.Model):
  16   author = db.UserProperty()
  17   content = db.StringProperty(multiline=True)
  18   date = db.DateTimeProperty(auto_now_add=True)
  19
  20 class MainPage(webapp.RequestHandler):
  21   def get(self):
  22     logging.debug("In MainPage handler");
  23     greetingsString = memcache.get(MEMCACHE_GREETINGS)
  24     if greetingsString is not None:
  25       logging.info("Retrieved greetings from memcache")
  26       greetings = pickle.loads(greetingsString)
  27     else:
  28       logging.info("No greetings in memcache, re-querying datastore")
  29       greetings_query = Greeting.all().order('-date')
  30       greetings = greetings_query.fetch(10)
  31       if not memcache.set(MEMCACHE_GREETINGS, pickle.dumps(greetings)):
  32         logging.error("Memcache set failed.")
  33
  34     if users.get_current_user():
  35       url = users.create_logout_url(self.request.uri)
  36       url_linktext = 'Logout'
  37     else:
  38       url = users.create_login_url(self.request.uri)
  39       url_linktext = 'Login'
  40
  41     template_values = {
  42       'greetings': greetings,
  43       'url': url,
  44       'url_linktext': url_linktext,
  45       }
  46
  47     path = os.path.join(os.path.dirname(__file__), 'index.html')
  48     self.response.out.write(template.render(path, template_values))
  49
  50
  51 class Guestbook(webapp.RequestHandler):
  52   def post(self):
  53     greeting = Greeting()
  54
  55     if users.get_current_user():
  56       greeting.author = users.get_current_user()
  57
  58     greeting.content = self.request.get('content')
  59     greeting.put()
  60     memcache.delete(MEMCACHE_GREETINGS)
  61     self.redirect('/')
  62
  63 application = webapp.WSGIApplication(
  64                                      [('/', MainPage),
  65                                       ('/sign', Guestbook)],
  66                                      debug=True)
  67
  68 def main():
  69   run_wsgi_app(application)
  70
  71 if __name__ == "__main__":
  72   main()