appengine/standard/ndb/queries/guestbook.py (46 lines of code) (raw):
# Copyright 2016 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the 'License');
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an 'AS IS' BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import cgi
from google.appengine.datastore.datastore_query import Cursor
from google.appengine.ext import ndb
import webapp2
class Greeting(ndb.Model):
"""Models an individual Guestbook entry with content and date."""
content = ndb.StringProperty()
date = ndb.DateTimeProperty(auto_now_add=True)
@classmethod
def query_book(cls, ancestor_key):
return cls.query(ancestor=ancestor_key).order(-cls.date)
class MainPage(webapp2.RequestHandler):
GREETINGS_PER_PAGE = 20
def get(self):
guestbook_name = self.request.get("guestbook_name")
ancestor_key = ndb.Key("Book", guestbook_name or "*notitle*")
greetings = Greeting.query_book(ancestor_key).fetch(self.GREETINGS_PER_PAGE)
self.response.out.write("<html><body>")
for greeting in greetings:
self.response.out.write(
"<blockquote>%s</blockquote>" % cgi.escape(greeting.content)
)
self.response.out.write("</body></html>")
class List(webapp2.RequestHandler):
GREETINGS_PER_PAGE = 10
def get(self):
"""Handles requests like /list?cursor=1234567."""
cursor = Cursor(urlsafe=self.request.get("cursor"))
greets, next_cursor, more = Greeting.query().fetch_page(
self.GREETINGS_PER_PAGE, start_cursor=cursor
)
self.response.out.write("<html><body>")
for greeting in greets:
self.response.out.write(
"<blockquote>%s</blockquote>" % cgi.escape(greeting.content)
)
if more and next_cursor:
self.response.out.write(
'<a href="/list?cursor=%s">More...</a>' % next_cursor.urlsafe()
)
self.response.out.write("</body></html>")
app = webapp2.WSGIApplication(
[
("/", MainPage),
("/list", List),
],
debug=True,
)