Question: PolyModelType that selects Model based on field value of parent

[Jacco]

I need to select the model based on a value in the parent model.

'State': {
  'Type': 'Task',
  'Resource': 'TheParentValue',
  'Parameters': {
    'FieldsDependingOnParentValue': 'HowToDoThat?'
  }

Is that possible?

I tried using a claim_function but the data passed is from the same level and not from the parent.

[lkraider]

Couldn't you match on the parameters content?

from schematics.models import Model
from schematics.types import serializable, StringType, IntType, PolyModelType

state1 = {
    'resource': 'StateType1',
    'parameters': {
        'x': '1',
        'y': '2',
    }
}
state2 = {
    'resource': 'StateType2',
    'parameters': {
        'z': 33,
    }
}

class ParametersType1(Model):
    x = StringType()
    y = StringType()


class ParametersType2(Model):
    z = IntType()

    @classmethod
    def _claim_polymorphic(cls, data):
        return data.get('z')


class StateClaim(Model):
    resource = StringType()
    parameters = PolyModelType([ParametersType1, ParametersType2])

s1 = StateClaim(state1)
s2 = StateClaim(state2)

print(s1, s1._data)
print(s2, s2._data)

<StateClaim instance> {'resource': 'StateType1', 'parameters': <ParametersType1 instance>}
<StateClaim instance> {'resource': 'StateType2', 'parameters': <ParametersType2 instance>}