guestbook_highrep/guestbook.py

   1 #!/usr/bin/env python
   2 #
   3 # Copyright 2007 Google Inc.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16 #
  17 import cgi
  18 import datetime
  19 import urllib
  20 import wsgiref.handlers
  21
  22 from google.appengine.ext import db
  23 from google.appengine.api import users
  24 from google.appengine.ext import webapp
  25
  26 # We set a parent key on the 'Greetings' to ensure that they are all in the same
  27 # entity group. Queries across the single entity group will be consistent.
  28 # However, the write rate should be limited to ~1/second.
  29
  30 def guestbook_key(guestbook_name=None):
  31   return db.Key.from_path('Guestbook', guestbook_name or 'default_guestbook')
  32
  33
  34 class Greeting(db.Model):
  35   author = db.UserProperty()
  36   content = db.StringProperty(multiline=True)
  37   date = db.DateTimeProperty(auto_now_add=True)
  38
  39
  40 class MainPage(webapp.RequestHandler):
  41   def get(self):
  42     self.response.out.write('<html><body>')
  43     guestbook_name=self.request.get('guestbook_name')
  44
  45     greetings = db.GqlQuery("SELECT * "
  46                             "FROM Greeting "
  47                             "WHERE ANCESTOR IS :1 "
  48                             "ORDER BY date DESC LIMIT 10",
  49                             guestbook_key(guestbook_name))
  50
  51     for greeting in greetings:
  52       if greeting.author:
  53         self.response.out.write('<b>%s</b> wrote:' % greeting.author.nickname())
  54       else:
  55         self.response.out.write('An anonymous person wrote:')
  56       self.response.out.write('<blockquote>%s</blockquote>' %
  57                               cgi.escape(greeting.content))
  58
  59     self.response.out.write("""
  60           <form action="/sign?%s" method="post">
  61             <div><textarea name="content" rows="3" cols="60"></textarea></div>
  62             <div><input type="submit" value="Sign Guestbook"></div>
  63           </form>
  64           <hr>
  65           <form>Gustbook name: <input value="%s" name="guestbook_name">
  66           <input type="submit" value="switch"></form>
  67         </body>
  68       </html>""" % (urllib.urlencode({'guestbook_name': guestbook_name}),
  69                     cgi.escape(guestbook_name)))
  70
  71
  72 class Guestbook(webapp.RequestHandler):
  73   def post(self):
  74     guestbook_name=self.request.get('guestbook_name')
  75     greeting = Greeting(parent=guestbook_key(guestbook_name))
  76
  77     if users.get_current_user():
  78       greeting.author = users.get_current_user()
  79
  80     greeting.content = self.request.get('content')
  81     greeting.put()
  82     self.redirect('/?' + urllib.urlencode({'guestbook_name': guestbook_name}))
  83
  84
  85 application = webapp.WSGIApplication([
  86   ('/', MainPage),
  87   ('/sign', Guestbook)
  88 ], debug=True)
  89
  90
  91 def main():
  92   wsgiref.handlers.CGIHandler().run(application)
  93
  94
  95 if __name__ == '__main__':
  96   main()