main.py

#!/usr/bin/env python
from google.appengine.ext import db
from google.appengine.ext import webapp
from google.appengine.ext.webapp import template
from google.appengine.ext.webapp import util
import simplejson

# the Todo model.
class Todo(db.Model):
    content = db.StringProperty()
    done = db.BooleanProperty()
    order = db.IntegerProperty()

class MainHandler(webapp.RequestHandler):
    def get(self):
        self.response.out.write(template.render("index.html", {}))

# the Todos collection handler - used to handle requests
# on the Todos collection.
class TodoListHandler(webapp.RequestHandler):
    # get all todos
    def get(self):
        # serialize all Todos, include the ID in the response
        todos = []
        for todo in Todo.all():
            todos.append({
                "id" : todo.key().id(),
                "content" : todo.content,
                "done" : todo.done,
                "order" : todo.order,
            })
        # send them to the client as JSON
        self.response.out.write(simplejson.dumps(todos))

    # create a todo
    def post(self):
        # load the JSON data of the new object
        data = simplejson.loads(self.request.body)

        # create the todo item
        todo = Todo(
            content = data["content"],
            done = data["done"],
            order = data["order"],
        ).put()

        # send it back, and include the new ID.
        self.response.out.write(simplejson.dumps({
            "id" : todo.id(),
            "content" : data["content"],
            "done" : data["done"],
            "order" : data["order"],
        }))

# The Todo model handler - used to handle requests with
# a specific ID.
class TodoItemHandler(webapp.RequestHandler):
    def put(self, id):
        # load the updated model
        data = simplejson.loads(self.request.body)

        # get it model using the ID from the request path
        todo = Todo.get_by_id(int(id))

        # update all fields and save to the DB
        todo.content = data["content"]
        todo.done = data["done"]
        todo.order = data["order"]
        todo.put()

        # send it back using the updated values
        self.response.out.write(simplejson.dumps({
            "id" : id,
            "content" : todo.content,
            "done" : todo.done,
            "order" : todo.order,
        }))

    def delete(self, id):
        # find the requested model and delete it.
        todo = Todo.get_by_id(int(id))
        todo.delete()

def main():
    application = webapp.WSGIApplication([
        ('/', MainHandler),

        # REST API requires two handlers - one with an ID and one without.
        ('/todos', TodoListHandler),
        ('/todos/(\d+)', TodoItemHandler),
    ], debug=True)
    util.run_wsgi_app(application)


if __name__ == '__main__':
    main()