Source code for ska_tmc_cdm.jsonschema.json_schema

The JSON Schema module contains methods for fetching version-specific JSON schemas
using interface uri and validating the structure of JSON against these schemas.

from ska_telmodel import schema
from ska_tmc_cdm.exceptions import JsonValidationError, SchemaNotFound

__all__ = ['JsonSchema']

[docs]class JsonSchema: # pylint: disable=too-few-public-methods """ JSON Schema use for validating the structure of JSON data """
[docs] @staticmethod def get_schema_by_uri(uri: str) -> schema.Schema: """ Retrieve JSON Schemas from remote server. :param uri: Interface Version URI :return: Interface schema :raises: SchemaNotFound if URI does not resolve to a schema """ try: return schema.schema_by_uri(uri) except ValueError as exc: raise SchemaNotFound(uri) from exc
[docs] @staticmethod def validate_schema(uri: str, instance: dict, strictness=None) -> None: """ Validate an instance dictionary under the given schema. strictness can be set from 0-2. Values equal: 0: permissive warnings 1: permissive errors and strict warnings 2: strict errors :param uri: The schema to validate with :param instance: The instance to validate :param strictness: strictness level :return: None, in case of valid data otherwise, it raises an exception. """ # use default strictness defined by Telescope Model unless overridden extra_kwargs = {} if strictness is not None: extra_kwargs["strictness"] = strictness try: return schema.validate(uri, instance, **extra_kwargs) except ValueError as exc: # Distinguish ValueErrors caused by schema not found from # ValueErrors caused by invalid JSON. try: schema.schema_by_uri(uri) except ValueError: if strictness is not None and strictness > 1: raise SchemaNotFound(uri) from exc else: raise JsonValidationError(uri, instance) from exc