Api(..., ordered=True) and Nested models → error in Swagger UI

[arkady]

When ordered=True is passed to Api (or a namespace), having Nested models causes an error in the Swagger UI

Example Code

from flask import Flask, request
from flask_restx import Api, Resource, fields, marshal_with

app = Flask(__name__)
api = Api(app, ordered=True)  ## ← Changing this to False removes error

AddressModel = api.model('Address', {'street': fields.String(required=True),
                                     'city': fields.String(required=True)
                                     })

PersonModel = api.model('Person', {'name': fields.String(required=True),
                                   'address': fields.Nested(AddressModel)})

@api.route('/hello')
class Hello(Resource):
    @api.expect(PersonModel, validate=True)
    @api.marshal_with(PersonModel)
    def put(self):
        return request.json

if __name__ == '__main__':
    app.run(debug=True)

Repro Steps (if applicable)

1. Run the code above (Python 2.7.12)
2. Navigate to localhost:5000
3. Click on the default namespace to expand it
4. Click on `/hello' endpoint

Expected Behavior

Should see Example Value and Model reflecting the nested models defined in code:

{
  "name": "string",
  "address": {
    "city": "string",
    "street": "string"
  }
}

Actual Behavior

The Example Value is missing the Nested Address model:

{
  "name": "string"
}

Also, an error pops up at the top of the Swagger UI page:

Resolver error at paths./hello.put.parameters.0.schema.properties.address.$ref
Could not resolve reference: Could not resolve pointer: /definitions/Address does not exist in document

Error Messages/Stack Trace

If applicable, add the stack trace produced by the error

Environment

• Python version: 2.7.12
• Flask version: 0.12.2
• Flask-RESTX version: 0.2.0
• Other installed Flask extensions: n/a