Validation

Every generated scalar is a real Django field, cleaned through Django's normal pipeline. The composite field then reconstructs the complete JSON document and validates it independently with jsonschema's Draft 2020-12 validator. Finally, application validators run. Custom fields cannot bypass document constraints.

Errors include JSON Pointer locations (/levels/0/points), appear in the widget summary and attach to the nearest editable child. Array locations account for deleted rows. Invalid schemas/unresolved references raise ImproperlyConfigured instead of being silently ignored. max_errors=100 bounds collected errors.

Resources and formats

configuration = JSONSchemaFormField(
    schema={"$ref": "urn:example:configuration"},
    schema_resources={
        "urn:example:configuration": {
            "type": "object",
            "properties": {"contact": {"type": "string", "format": "email"}},
            "required": ["contact"],
            "additionalProperties": False,
        },
    },
    validate_formats=True,
)

Alternatively pass schema_registry=referencing.Registry(...) for explicitly controlled resource retrieval. The default registry does not access the network. format_checker accepts a jsonschema.FormatChecker, including custom checks. Document format checks default to off; built-in Django format fields retain their own validation. Content keywords do not decode files automatically.

For validation outside a form:

from django_native_jsonform import JSONSchemaValidator

validator = JSONSchemaValidator(SCHEMA, validate_formats=True)
validator(value)  # Raises JSONFormValidationError on an invalid document.
issues = validator.issues(value)  # SchemaIssue path, pointer, keyword, message.

normalize_schema translates legacy choices, boolean leaf required and readonly without mutating the original schema or data in const/default.

Whole-value validators

Pass Django validators to JSONSchemaFormField as usual:

def validate_configuration(value):
    if value.get("starts_on") and value.get("ends_on"):
        if value["starts_on"] > value["ends_on"]:
            raise ValidationError("The date range is invalid.")


configuration = JSONSchemaFormField(
    schema=SCHEMA,
    validators=[validate_configuration],
)

Errors attached to a child path

Use JSONFormValidationError to put errors next to generated fields:

from django_native_jsonform import JSONFormValidationError


def validate_configuration(value):
    errors = {}
    if value.get("path", "").endswith("/"):
        errors["path"] = "Path must not end with /."
    for index, level in enumerate(value.get("levels", [])):
        if level.get("points", 0) < 0:
            errors[f"levels.{index}.points"] = "Points cannot be negative."
    if errors:
        raise JSONFormValidationError(
            "Invalid configuration",
            errors=errors,
        )

Paths accept legacy dot notation or JSON Pointer (/levels/0/points). Use JSON Pointer for property names containing dots or slashes. Array indices refer to the reconstructed document, after deleted rows are removed. Errors attach to the nearest active editable node and remain available in the widget summary.

Custom Django fields

A registered field or an override may implement any normal Django validation: validators, to_python, validate, and run_validators. Its cleaned value is serialized into JSON through the built-in serializer or a path-specific serialize callable.

The built-in serializer handles Django models/querysets, Decimal, date/time objects, and UUIDs.