Appengine katse: autent ja andmebaas
Allikas: Lambda
import cgi
import datetime
import urllib
import wsgiref.handlers
from google.appengine.ext import db
from google.appengine.api import users
from google.appengine.ext import webapp
from google.appengine.ext.webapp.util import run_wsgi_app
class Greeting(db.Model):
"""Models an individual Guestbook entry with an author, content, and date."""
author = db.UserProperty()
content = db.StringProperty(multiline=True)
date = db.DateTimeProperty(auto_now_add=True)
def guestbook_key(guestbook_name=None):
"""Constructs a datastore key for a Guestbook entity with guestbook_name."""
return db.Key.from_path('Guestbook', guestbook_name or 'default_guestbook')
class MainPage(webapp.RequestHandler):
def get(self):
user = users.get_current_user()
if user:
self.response.out.write('<html><body>')
guestbook_name=self.request.get('guestbook_name')
# Ancestor Queries, as shown here, are strongly consistent with the High
# Replication datastore. Queries that span entity groups are eventually
# consistent. If we omitted the ancestor from this query there would be a
# slight chance that Greeting that had just been written would not show up
# in a query.
greetings = db.GqlQuery("SELECT * "
"FROM Greeting "
"WHERE ANCESTOR IS :1 "
"ORDER BY date DESC LIMIT 10",
guestbook_key(guestbook_name))
for greeting in greetings:
if greeting.author:
self.response.out.write(
'<b>%s</b> wrote:' % greeting.author.nickname())
else:
self.response.out.write('An anonymous person wrote:')
self.response.out.write('<blockquote>%s</blockquote>' %
cgi.escape(greeting.content))
self.response.out.write("""
<form action="/sign?%s" method="post">
<div><textarea name="content" rows="3" cols="60"></textarea></div>
<div><input type="submit" value="Sign Guestbook"></div>
</form>
<hr>
<form>Guestbook name: <input value="%s" name="guestbook_name">
<input type="submit" value="switch"></form>
</body>
</html>""" % (urllib.urlencode({'guestbook_name': guestbook_name}),
cgi.escape(guestbook_name)))
else:
self.redirect(users.create_login_url(self.request.uri))
class Guestbook(webapp.RequestHandler):
def post(self):
# We set the same parent key on the 'Greeting' to ensure each greeting is in
# the same entity group. Queries across the single entity group will be
# consistent. However, the write rate to a single entity group should
# be limited to ~1/second.
guestbook_name = self.request.get('guestbook_name')
greeting = Greeting(parent=guestbook_key(guestbook_name))
if users.get_current_user():
greeting.author = users.get_current_user()
greeting.content = self.request.get('content')
greeting.put()
self.redirect('/?' + urllib.urlencode({'guestbook_name': guestbook_name}))
application = webapp.WSGIApplication([
('/', MainPage),
('/sign', Guestbook)
], debug=True)
def main():
run_wsgi_app(application)
if __name__ == '__main__':
main()
