Source code for cis_interface.metaschema.properties.TypeMetaschemaProperty
from cis_interface.metaschema.datatypes import (
get_registered_types, get_type_class, MetaschemaTypeError)
from cis_interface.metaschema.properties import register_metaschema_property
from cis_interface.metaschema.properties.MetaschemaProperty import MetaschemaProperty
def _specificity_sort_key(item):
return -item[1].specificity
[docs]@register_metaschema_property
class TypeMetaschemaProperty(MetaschemaProperty):
r"""Type property with validation of new properties."""
name = 'type'
_replaces_existing = True
_validate = False
[docs] @classmethod
def encode(cls, instance, typedef=None):
r"""Method to encode the property given the object.
Args:
instance (object): Object to get property for.
typedef (object, None): Template value in type definition to use
for initializing encoding some cases. Defaults to None and
is ignored.
Returns:
object: Encoded property for instance.
"""
type_registry = get_registered_types()
for t, cls in sorted(type_registry.items(), key=_specificity_sort_key):
if cls.validate(instance):
return t
raise MetaschemaTypeError(
"Could not encode 'type' property for Python type: %s"
% type(instance))
[docs] @classmethod
def compare(cls, prop1, prop2, root1=None, root2=None):
r"""Method to determine compatiblity of one property value with another.
This method is not necessarily symmetric in that the second value may
not be compatible with the first even if the first is compatible with
the second.
Args:
prop1 (object): Property value to compare against prop2.
prop2 (object): Property value to compare against.
Yields:
str: Comparision failure messages.
"""
type_cls = get_type_class(prop1)
if not type_cls.issubtype(prop2):
yield "Type '%s' is not a subtype of type '%s'" % (prop1, prop2)
[docs] @classmethod
def normalize(cls, normalizer, value, instance, schema):
r"""Method to normalize the instance based on the property value.
Args:
normalizer (Normalizer): Normalizer class.
value (object): Property value.
instance (object): Object to normalize.
schema (dict): Schema containing this property.
Returns:
object: Normalized object.
"""
if isinstance(value, (list, tuple)):
v0 = value[0]
for v in value:
t = get_type_class(v)
if t.validate(v):
v0 = v
break
type_cls = get_type_class(v0)
else:
type_cls = get_type_class(value)
return type_cls.normalize(instance)