Upgrading Flask-RESTful and the settings object is gone. How to format dates now?

Question

I need to update an application from Flask-RESTful 0.2.5 to 0.3.5.

My API has over 40 endpoints, approximately 25 of which have entities that have datetime fields in them. When using 0.2.5, I followed the excellent provided in this Stack Overflow question and placed the following function in my __init__.py file:

class MyApiJsonEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, (datetime.datetime, datetime.date, datetime.time)):
            return obj.isoformat()
        elif isinstance(obj, Decimal):
            return str(obj)
        return json.JSONEncoder.default(self, obj)

flask.ext.restful.representations.json.settings["cls"] = MyApiJsonEncoder

and this worked wonderfully. Now when upgrading to 0.3.5, the settings object is no more.

File ".........../api/__init__.py", line 35, in <module>
  flask.ext.restful.representations.json.settings["cls"] = MyApiJsonEncoder
AttributeError: 'module' object has no attribute 'settings'

Okay, so I looked into the documentation and found that I should be using @marshal_with. But this scares me! It appears that I have to go into every single endpoint that has a date or datetime field and put in a fields dictionary with a @marshal_with decorator. In fact, it appears that this dictionary not just state that I want my dates and datetimes in ISO8601 format but that other fields must be designated with their marshalling preferences as well.

I hope I am reading this wrong.

My question is: how can I, with Flask-RESTful 0.3.5, state globally, and non-instrusively, that I want all dates to be marshalled in ISO8601 format. (By non-intrusively I mean I don't want to muck up my existing 40 endpoints.)

Answer 1

You now set the encoder as the cls property of a dict set as the RESTFUL_JSON attribute of the application configuration.

An explanation of how to set this attribute is here.