Source code for yggdrasil.metaschema.datatypes.FixedMetaschemaType

import jsonschema
import copy
from yggdrasil.metaschema.datatypes import (
    compare_schema, generate_data, resolve_schema_references)
from yggdrasil.metaschema.datatypes.MetaschemaType import MetaschemaType


[docs]def create_fixed_type_class(name, description, base, fixed_properties, target_globals=None, class_name=None, **kwargs): r"""Create a fixed class. Args: name (str); Name of the fixed type. description (str): Description of the fixed type. base (MetaschemaType): Base class that should be used. fixed_properties (dict): Mapping between properties that are fixed and the value they are fixed to. target_globals (dict, optional): Globals dictionary for module where the fixed class should be added. If None, the new class is returned. Defaults to None. class_name (str, optional): Name that should be given to the class. If not provided, defaults to '<name.title()>MetaschemaType'. **kwargs: Additional keyword arguments are treated as attributes that should be set on the fixed class. Returns: str, class: The name of the class created if target_globals is provided, the created class if target_globals is None. """ if class_name is None: class_name = str('%sMetaschemaType' % name.title()) iattr = {'name': name, 'description': description, 'fixed_properties': fixed_properties, 'specificity': base.specificity + 1} iattr.update(kwargs) for k in ['properties', 'definition_properties', 'metadata_properties']: iattr[k] = copy.deepcopy(getattr(base, k)) for x in fixed_properties.keys(): if x == 'type': continue if x in iattr[k]: iattr[k].remove(x) new_cls = type(class_name, (FixedMetaschemaType, base, ), iattr) if target_globals is not None: target_globals[new_cls.__name__] = new_cls del new_cls return name else: return new_cls
[docs]class FixedMetaschemaType(MetaschemaType): r"""Class that should be used to alias another type, but with certain properties fixed. Arguments: **kwargs: All keyword arguments are assumed to be type definition properties which will be used to validate serialized/deserialized messages. Attributes: fixed_properties (dict): Type properties of the parent class that are fixed and the values they are fixed to. """ is_fixed = True fixed_properties = {}
[docs] @classmethod def base(cls): r"""Get the type that this type is a fixed version of.""" return cls.__bases__[-1]
[docs] @classmethod def typedef_base2fixed(cls, typedef): r"""Transform a type definition from the unfixed base type to the fixed type alias by removing fixed properties. Args: typedef (dict): Type definition for the unfixed base type that might include properties that are fixed in the base. Returns: dict: Copy of type definition with fixed properties removed. """ out = copy.deepcopy(typedef) if out.get('type', None) == cls.base().name: out.update(cls.fixed_properties) errors = [e for e in compare_schema(typedef, out)] if errors: error_msg = "Error(s) in comparison with fixed properties.\n" for e in errors: error_msg += '\t%s\n' % e raise Exception(error_msg) for k, v in cls.fixed_properties.items(): if k in out: del out[k] out['type'] = cls.name return out
[docs] @classmethod def typedef_fixed2base(cls, typedef): r"""Transform a type definition from the fixed alias to the unfixed base by setting the fixed properties if they are not already present. Args: typedef (dict): Type definition for the fixed alias type. Returns: dict: Copy of type definition with fixed properties added. """ out = copy.deepcopy(typedef) if out.get('type', None) == cls.name: for k, v in cls.fixed_properties.items(): if (k == 'type') or (k not in cls.base().properties): continue if k in out: assert(out[k] == v) else: out[k] = v out['type'] = cls.base().name if 'definitions' in cls.fixed_properties: out['definitions'] = cls.fixed_properties['definitions'] out = resolve_schema_references(out) out.pop('definitions') # if cls.base().is_fixed: # out = cls.base().typedef_fixed2base(out) return out
[docs] @classmethod def issubtype(cls, t): r"""Determine if this type is a subclass of the provided type. Args: t (str): Type name to check against. Returns: bool: True if this type is a subtype of the specified type t. """ if super(FixedMetaschemaType, cls).issubtype(t): return True if cls.base().issubtype(t): return True return False
[docs] @classmethod def updated_fixed_properties(cls, obj): r"""Get a version of the fixed properties schema that includes information from the object. Args: obj (object): Object to use to put constraints on the fixed properties schema. Returns: dict: Fixed properties schema with object dependent constraints. """ return copy.deepcopy(cls.fixed_properties)
[docs] @classmethod def validate(cls, obj, raise_errors=False): r"""Validate an object to check if it could be of this type. Args: obj (object): Object to validate. raise_errors (bool, optional): If True, errors will be raised when the object fails to be validated. Defaults to False. Returns: bool: True if the object could be of this type, False otherwise. """ if not super(FixedMetaschemaType, cls).validate( obj, raise_errors=raise_errors): return False try: obj = cls.coerce_type(obj) jsonschema.validate(obj, cls.updated_fixed_properties(obj), cls=cls.validator()) except (jsonschema.exceptions.ValidationError, AssertionError): if raise_errors: raise return False return True
# This code was unused by any of the test cases, but is kept in case it is # needed in the future # @classmethod # def encode_type(cls, obj, typedef=None, **kwargs): # r"""Encode an object's type definition. # Args: # obj (object): Object to encode. # typedef (dict, optional): Type properties that should be used to # initialize the encoded type definition in certain cases. # Defaults to None and is ignored. # **kwargs: Additional keyword arguments are treated as additional # schema properties. # Raises: # YggTypeError: If the object is not the correct type. # Returns: # dict: Encoded type definition. # """ # type_from_base = False # if typedef is None: # typedef = {} # for k, v in cls.fixed_properties.items(): # if (k == 'type'): # continue # elif (typedef.get(k, v) != v) or (kwargs.get(k, v) != v): # type_from_base = True # break # if not type_from_base: # return super(FixedMetaschemaType, cls).encode_type( # obj, typedef=typedef, **kwargs) # if isinstance(typedef, dict): # typedef = cls.typedef_fixed2base(typedef) # kwargs = cls.typedef_fixed2base(kwargs) # out = cls.base().encode_type(obj, typedef=typedef, **kwargs) # out = cls.typedef_base2fixed(out) # return out
[docs] @classmethod def check_encoded(cls, metadata, typedef=None, raise_errors=False, **kwargs): r"""Checks if the metadata for an encoded object matches the type definition. Args: metadata (dict): Meta data to be tested. typedef (dict, optional): Type properties that object should be tested against. Defaults to None and object may have any values for the type properties (so long as they match the schema. raise_errors (bool, optional): If True, any errors determining that encoded object is not of this type will be raised. Defaults to False. **kwargs: Additional keyword arguments are passed to the parent class. Returns: bool: True if the metadata matches the type definition, False otherwise. """ try: out = cls.typedef_base2fixed(metadata) except Exception: if raise_errors: raise return False return super(FixedMetaschemaType, cls).check_encoded( out, typedef=typedef, raise_errors=raise_errors, **kwargs)
[docs] @classmethod def extract_typedef(cls, metadata): r"""Extract the minimum typedef required for this type from the provided metadata. Args: metadata (dict): Message metadata. Returns: dict: Encoded type definition with unncessary properties removed. """ out = cls.typedef_base2fixed(metadata) out = super(FixedMetaschemaType, cls).extract_typedef(out) return out
[docs] def update_typedef(self, **kwargs): r"""Update the current typedef with new values. Args: **kwargs: All keyword arguments are considered to be new type definitions. If they are a valid definition property, they will be copied to the typedef associated with the instance. Returns: dict: A dictionary of keyword arguments that were not added to the type definition. """ typename = kwargs.get('type', None) if typename == self.__class__.base().name: kwargs = self.__class__.typedef_base2fixed(kwargs) out = super(FixedMetaschemaType, self).update_typedef(**kwargs) return out
@classmethod def _generate_data(cls, typedef, **kwargs): r"""Generate mock data for the specified type. Args: typedef (dict): Type definition. Returns: object: Python object of the specified type. """ typedef0 = cls.typedef_fixed2base(typedef) return generate_data(typedef0, **kwargs)