Nested entities in Google App Engine. Do I do it right?
- by Aleksandr Makov
Trying to make most of the GAE Datastore entities concept, but some doubts drill my head.
Say I have the model:
class User(ndb.Model):
email = ndb.StringProperty(indexed=True)
password = ndb.StringProperty(indexed=False)
first_name = ndb.StringProperty(indexed=False)
last_name = ndb.StringProperty(indexed=False)
created_at = ndb.DateTimeProperty(auto_now_add=True)
@classmethod
def key(cls, email):
return ndb.Key(User, email)
@classmethod
def Add(cls, email, password, first_name, last_name):
user = User(parent=cls.key(email),
email=email,
password=password,
first_name=first_name,
last_name=last_name)
user.put()
UserLogin.Record(email)
class UserLogin(ndb.Model):
time = ndb.DateTimeProperty(auto_now_add=True)
@classmethod
def Record(cls, user_email):
login = UserLogin(parent=User.key(user_email))
login.put()
And I need to keep track of times of successful login operations. Each time user logs in, an UserLogin.Record() method will be executed. Now the question — do I make it right?
Thanks.
EDIT 2
Ok, used the typed arguments, but then it raised this: Expected Key instance, got User(key=Key('User', 5418393301680128), created_at=datetime.datetime(2013, 6, 27, 10, 12, 25, 479928), email=u'[email protected]', first_name=u'First', last_name=u'Last', password=u'password'). It's clear to understand, but I don't get why the docs are misleading? They implicitly propose to use:
# Set Employee as Address entity's parent directly...
address = Address(parent=employee)
But Model expects key. And what's worse the parent=user.key() swears that key() isn't callable. And I found out the user.key works.
EDIT 1
After reading the example form the docs and trying to replicate it — I got type error:
TypeError('Model constructor takes no positional arguments.'). This is the exacto code used:
user = User('[email protected]', 'password', 'First', 'Last')
user.put()
stamp = UserLogin(parent=user)
stamp.put()
I understand that Model was given the wrong argument, BUT why it's in the docs?
