Ferris 3 example with custom properties

custom_service.py

import ferris3
import endpoints
import protopigeon
from protorpc import messages
from google.appengine.ext import ndb


class ExampleProperty(ndb.StringProperty):
    def _to_base_type(self, value):
        return "---" + str(value) + "---"

    def _from_base_type(self, value):
        return value.strip('-')


class ExampleModel(ndb.Model):
    normal = ndb.StringProperty()
    custom = ExampleProperty()


class ExamplePropertyConverter(protopigeon.converters.Converter):
    @staticmethod
    def to_field(Model, property, count):
        return messages.StringField(count, repeated=property._repeated, required=property._required)


protopigeon.converters.converters["ExampleProperty"] = ExamplePropertyConverter


@ferris3.auto_service
class CustomService(ferris3.Service):
    list = ferris3.hvild.list(ExampleModel)
    insert = ferris3.hvild.insert(ExampleModel)