Deferred validators and missing

[mazvv]

Hi
There is a problem with deferred validators and missing. For example schema

class CrosspaymentSchema(ResourceSchema):
    date = colander.SchemaNode(
        Date(),
    )
    account_from_id = colander.SchemaNode(
        colander.Integer(),
        missing=None,
        validator=account_from_validator
    )
    subaccount_from_id = colander.SchemaNode(
        colander.Integer(),
        missing=None,
    )

and validator

class AccountFromValidator(object):
    def __init__(self, request):
        self.request = request

    def __call__(self, node, value):
        request = self.request
        subaccount_from_id = cast_int(request.params.get('subaccount_from_id'))
        if not value and not subaccount_from_id:
            raise colander.Invalid(
                node,
                _(u'Set at least one account or subaccount from any section'),
            )
        if value and subaccount_from_id:
            raise colander.Invalid(
                node,
                _(u'Set only account or subaccount or clear both')
            )

@colander.deferred
def account_from_validator(node, kw):
    request = kw.get('request')
    return colander.All(AccountFromValidator(request))

I expect to get 'Set at least one account or subaccount from any section' error if both account_from_id and subaccount_from_id is empty. But I have not validation errors.

[Eger37]

May be you need to bind your schema? https://docs.pylonsproject.org/projects/colander/en/latest/binding.html

[mvattuone]

I also ran into this issue, and our schema is indeed bound.

The only way I was able to resolve it was by overriding the missing values in deserialize - this seems like a hack, but I don't see a better way as of now.

Ideally it would be great to find some way to have the validators run even if missing sets None - I imagine the problem is that None implies there is no value, or nothing to validate, since None is valid according to missing

    # For some `SchemaNode`
    def deserialize(self, cstruct):
        request = self.bindings["request"]
        blah = request.json_body.get("blah")

        if (
            blah is None
            or blah is ""
        ):
            self.missing = required
            self.missing_msg = "Custom Message"

        return super().deserialize(cstruct)