AppEngine，实体不见了？

Question

So I have 2 model classes:

class Profile(db.Model):
  """Profiles are merely lighter versions of Users. The are only used for the
  purpose of notification
  """
  created_at = db.DateTimeProperty(auto_now_add=True)
  created_by = None   # TODO User class
  name = db.StringProperty()
  email = db.EmailProperty()
  phone = db.PhoneNumberProperty()


class Notification(db.Model):
  LEVELS = {
      'INFO': 'INFO',
      'WARNING': 'WARNING',
      'CRITICAL': 'CRITICAL'
  }
  created_by = None   # TODO user class
  created_at = db.DateTimeProperty(auto_now_add=True)
  profile = db.ReferenceProperty(Profile, collection_name='notifications')
  level = db.StringProperty()

This is what my JSONencoder looks like:

class JsonEncoder(json.JSONEncoder):
  def default(self, obj):
    if isinstance(obj, datetime.datetime):
      return obj.isoformat()
    elif isinstance(obj, Profile):
      return dict(key=obj.key().id_or_name(),
                  name=obj.name, email=obj.email, phone=obj.phone)
    elif isinstance(obj, Limits):
      return None
    else:
      return json.JSONEncoder.default(self, obj)

Basically, one can assign a notification to a profile such that when a notification fires, all the profiles associated with that notification will be notified.

In my html, I have a form allowing users to create a notifiation:

  <form action="{{ url_for('new_notification') }}" method=post>

    <!-- If disabled=true we won't send this in the post body -->
    Name:
    <input name='name' type='text' value='Select from above' disabled=true />
    <br/>

    <!-- if type=hidden html will still send this in post body -->
    <input name='key' type='hidden' value='Select from above' />

    Type:
    <select name='level'>
      {% for k,v in notification_cls.LEVELS.iteritems() %}
      <option value="{{ v }} ">{{ k }}</option>
      {% endfor %}
    </select>
    <br/>

    <input type="submit" value="Submit">
  </form>

However, I am seeing some strange things happening in my method to create a notification:

@app.route('/notifications/new/', methods=['GET', 'POST'])
def new_notification():
  """Displays the current notifications avaiable for each profiles
  """
  if request.method == 'GET':
    return render_template('new_notification.html',
                           notification_cls=Notification)
  else:
    profile_key_str = request.form.get('key', None)
    level = request.form.get('level', None)
    if not profile_key_str or not level:
      abort(404)

    profile_key = db.Key.from_path('Profile', profile_key_str)

    profile = Profile.get(profile_key)
    print profile     # This results in None??

    notification = Notification(parent=profile)   # Ancestor for strong consistency
    notification.profile = profile_key
    notification.level = level
    notification.put()
    return redirect(url_for('list_notifications'), code=302)

So a user can create a profile on the new_notifications page. After that, my server will send the newly created entity's key via ajax to the same page containing the form. This will set the hidden input's value.

Somehow, in my new_notification method, Profile does not exist!!!! I am sort of suspicious of AppEngine's "eventual consistency" policy but I've been waiting for 30 mins and the results is still None.

Any ideas what I am doing wrong?

EDIT:

I forgot to include the method which calls the JSONEncoder for my JS

@app.route('/profiles/', methods=['GET'])
def ajax_list_profiles():
  def _dynatable_wrapper(profiles):
    return {'records': profiles,
            'queryRecordCount': len(profiles),
            'totalRecordCount': len(profiles)}
  name = request.args.get('queries[search]', None)
  if not name:
    profiles = db.Query(Profile).order('name').fetch(None)
    return json.dumps(_dynatable_wrapper(profiles), cls=JsonEncoder)
  else:
    profiles = db.Query(Profile).filter("name =", name).order('name').fetch(None)
    return json.dumps(_dynatable_wrapper(profiles), cls=JsonEncoder)

Answer 1

您可能希望将int用作键路径，否则它将认为其是键名。