app-engine-ndb

I'm working on providing an API via GAE that will allow users to page forwards and backwards through a set of entities. I've reviewed the section about cursors on the NDB Queries documentation page , which includes some sample code that describes how to page backwards through query results, but it doesn't seem to be working as desired. I'm using GAE Development SDK 1.8.8. Here's a modified version of that example that creates 5 sample entities, gets and prints the first page, steps forward into and prints the second page, and attempts to step backwards and print the first page again: import

I am leveraging ndb's to_dict method to convert an object's properties into a python dict. From everything I can tell, this method does not include the object's key or parent within the dict as per the documentation: https://developers.google.com/appengine/docs/python/ndb/modelclass#Model_to_dict However for my situation I need the key to be in the dict. My preference would be to leverage the builtin method and subclass it or something similar rather than create my own to_dict method. What is the best way to accomplish this or am I missing something obvious? Thanks in advance. FYI: I am not

In app engine transactions documentation I have found the following note: Note: If your app receives an exception when submitting a transaction, it does not always mean that the transaction failed. You can receive Timeout, TransactionFailedError, or InternalError exceptions in cases where transactions have been committed and eventually will be applied successfully. Whenever possible, make your Datastore transactions idempotent so that if you repeat a transaction, the end result will be the same. This is quite general information and I wasn't able to find more details. I have the following

I've this data model (I made it, so if there's a better way to do it, please let me know). Baically I've Club that can have many Courses . now I want to know all the members and instructors of a Club. members and instructors are stored in the Course model, and Club has a reference to them. See the code.. class Course(ndb.Model): ... instructor_keys = ndb.KeyProperty(kind="User", repeated=True) member_keys = ndb.KeyProperty(kind="User", repeated=True) @property def instructors(self): return ndb.get_multi(self.instructor_keys) @property def members(self): return filter(lambda x: x.is_active, ndb

So let's say I have a webapp which just lets users save their hobbies. So I have Kind like this: class Hobby(ndb.Model): hobby_name = ndb.StringProperty() Users just create Hobby entities using this form: <form action="/new-hobby" method="post"> <input type="text" name="hobby_name" id="new-hobby" /> <input type="submit" value="Save New Hobby" /> </form> Then this form is handled by this: # Handles /new-hobby class NewHobby(webapp2.RequestHandler): def post(self): hobby_name = self.request.get('hobby_name') if hobby_name: h = Hobby(hobby_name = hobby) h.put() app = webapp2.WSGIApplication([ ('

How do I work with ndb.StructuredProperty(repeated = True) properties when it comes to designing their forms and handlers? Consider this example: I've got 3 ndb.Model kinds: SkilledPerson , his Education , and his (work) Experience . The latter two are StructuredProperty types of SkilledPerson. class SkilledPerson(ndb.Model): name = ndb.StringProperty() birth = ndb.DateProperty() education = ndb.StructuredProperty(Education, repeated = True) experience = ndb.StructuredProperty(Experience, repeated = True) class Education(ndb.Model): institution = ndb.StringProperty() certification = ndb

I have a simple little "Observation" class: from google.appengine.ext import ndb class Observation(ndb.Model): remote_id = ndb.StringProperty() dimension_id = ndb.IntegerProperty() metric = ndb.StringProperty() timestamp_observed = ndb.StringProperty() timestamp_received = ndb.DateTimeProperty(auto_now_add=True) @classmethod def query_book(cls): return cls.query() I can run projection queries against the Datastore to return only certain columns. E.g: observations = Observation.query().fetch(projection=[Observation.dimension_id]) This works nicely, but I only want unique results. The