Integration for custom model validators is missing

[penenkel]

My goal is to to integrate a custom validator with ErrorMap support, i.e. one that raises a JSONSchemaValidationError. I expect the error messages to be displayed on the individual inputs like with the buildin schema validator.

Adding such a validator to the jsonform.JSONField like you would for model validation does not work. The validator is executed but the ErrorMap is apparently not propagated to the widget.

As far as I know there is a difference between (model-)field validators and form-field validators. From looking at the code I saw that jsonform.JSONFormField overrides django.forms.JSONField.run_validators to capture JSONSchemaValidationError s and propagate the ErrorMap.
jsonform.JSONField on the other hand does not override the corresponding django.db.models.JSONField.run_validator and thus ErrorMaps from model validators are not propagated to the widget.

I propose to add such an override.

I'm currently working around that issue by using my own model-field class and overriding .formfield() to inject the validator into the form-field validation pipeline instead of using the model-field validation pipeline.

class MyField(jsonform.JSONField):
    SCHEMA = {
        "type": "array",
        "items": {"type": "string"},
        "uniqueItems": True,
    }

    def __init__(self, *args, **kwargs):
        super().__init__(schema=self.SCHEMA, *args, **kwargs_)

    def formfield(self, **kwargs):
        return super().formfield(**{"validators": [MyValidator()], **kwargs})