Updating a document with a data_relation that is nullable fails

[jdalegonzalez]

Expected Behavior

Given a schema that defines a data_relation but also marks the field as "nullable", one would expect that setting the field to "None" would be legal.

### Given the following schema....
USER_SCHEMA = {
    'email': {
        'type': 'string',
        'minlength': 1,
        'maxlength': 254,
        'required': True,
        'unique': True,
    },
    'name': {
        'type': 'string',
    },
    'title': {
        'type': 'string',
    },
    employer: {
        'type': 'objectid',
        'required': False,
        'nullable': True,
        'data_relation': {
            'resource': 'company,
            'field': '_id',
            'embeddable': True
        },
    }
}

#### The following patch will fail but should succeed.
def test_patch_user():
    payload = {'employer': None}
    patch_header = {
        'Authorization': TOKEN1['Authorization'],
        'If-Match': user_etag
    }
    req = requests.patch(BASE_URL + '/users/' + user_id,
                         headers=patch_header, json=payload)
    assert req.status_code == 200

Actual Behavior

Instead, eve generates an error saying: "value 'None' must exist in resource 'companies', field '_id'."

Environment

• Python version: 3.6.5
• Eve version: 0.8

[nicolaiarocci]

Excellent, thank you.

[jdalegonzalez]

For those folks that have this issue and don't want to wait for a fix, I temporarily solved it by extending the validator and overriding the _validate_data_relation like so....

class MyValidator(Validator):
    def _validate_data_relation(self, relation, field, value):
        """ {'type': 'dict',
             'schema': {
                'resource': {'type': 'string', 'required': True},
                'field': {'type': 'string', 'required': True},
                'embeddable': {'type': 'boolean', 'default': False},
                'version': {'type': 'boolean', 'default': False}
             }} """

        if value:
            super(C2M2validator, self)._validate_data_relation(
                relation, field, value
            )
    # def _validate_data_relation

[nicolaiarocci]

Should be fixed now!

[Kobzol]

I'm having the same error and it still doesn't work even with Eve eb6d37d. I'm sending the ref in JSON with value null, so probably the conversion from null to None doesn't work properly.

[nicolaiarocci]

@Kobzol can't reproduce it.

Sending a {"employer": null} document to Eve 0.8.1-dev via Postman, to an endpoint defined as in the test added with eb6d37d returns 201 with the following document:

{
    "employer": null,
    "_updated": "Wed, 08 Aug 2018 08:11:16 GMT",
    "_created": "Wed, 08 Aug 2018 08:11:16 GMT",
    "_etag": "3d9eb0dcb165523586d796aff503401aacf5709d",
    "_id": "5b6aa5a4ee9f91392db8ad4c",
    "_links": {
        "self": {
            "title": "Employee",
            "href": "employee/5b6aa5a4ee9f91392db8ad4c"
        }
    },
    "_status": "OK"
}

[nicolaiarocci]

PS: if I switch back to v0.8 (current stable), I get a 422 as reported and expected

[Kobzol]

Sorry, I guess that I didn't update the version correctly using pip, I tried it with a clean clone and now it works. Thank you very much.