Field Generator

This tutorial is about the use of JSONField with parameter JSONField.as_string set to False. Lets start with a model for a general data feed:

class Feed(odm.StdModel):
    name = odm.SymbolField()
    data = odm.JSONField(as_string=False)

lets create an instance:

feed = Feed(name='goog').save()
feed.data = {'price': {'bid': 750, 'offer':751},
             'volume': 2762355371,
             'mkt_cap': '255B',
             'pe': 23}
feed.save()

When loading the instance one can access all the fields in the following way:

feed.data['price']['bid']
feed.data['price']['offer']

or equivalently:

feed.data__price__bid
feed.data__price__offer