Nested Custom Coercers Not Applied

Used Cerberus version / latest commit: Cerberus==1.1

• I consulted these documentations:

  • http://docs.python-cerberus.org/en/stable/
  • http://docs.python-cerberus.org/en/latest/

• I consulted these sections of the docs (add more lines as necessary):

  • …
  • …

• I found nothing relevant to my problem in the docs.

• I found the documentation not helpful to my problem.

• I have the capacity to improve the docs when my problem is solved.

• I have the capacity to submit a patch when a bug is identified.

---

Support request / Bug report

I am trying to apply a custom coercer to a nested item. I do not believe this is working properly. To simplify this, I modified the example code from the documentation to demonstrate the issue:

class MyNormalizer(Validator):
    def __init__(self, multiplier, *args, **kwargs):
        super(MyNormalizer, self).__init__(multiplier=multiplier, *args, **kwargs)
        self.multiplier = multiplier

    def _normalize_coerce_multiply(self, value):
        return value * self.multiplier

schema = {
    'foo': {
        'type': 'list',
        'schema': {
            'sub_foo': {
                'coerce': 'multiply'
            }
        }
    }
}

document = {'foo': [{'sub_foo': 2}]}
MyNormalizer(2).normalized(document, schema)

# Expected Output: {'foo': [{'sub_foo': 4}]}
# Output: {'foo': [{'sub_foo': 2}]}

I believe the schema definition / custom Validator class is accurate. Please let me know if this is not the case.

[funkyfuture]

@fermuch normalization rules in *of rules are not applied. see #344 / 17e786b

@sireliah at the time values are coerced, the document will not have a field with any rules in the schema. see #345

[sireliah]

Hey, I found similar issue with nested structures when you:

• rename the parent element
• try to change child element

from cerberus import Validator

schema = {
    "rows": {
        "type": "list",
        "rename": "ROWS",
        "schema": {
            "type": "dict",
            "schema": {
                "reference": {
                    "type": "string",
                    "coerce": lambda x: "%s MODIFIED HERE " % x
                },
            }
        }
    }
}


to_normalize = {"rows": [{"reference": "aaaaa"}]}

v = Validator(schema)

v.normalized(to_normalize)

Out[29]: {'ROWS': [{'reference': 'aaaaa'}]}


Expected:
 {'ROWS': [{'reference': 'aaaaa MODIFIED HERE '}]}

It would be nice this to work in such way that you are able to modify the parent element first and then apply changes to all child elements. If there is no easy fix, I can try to find a way.