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from inspect import isclass
import six
from ..pyutils.init_subclass import InitSubclassMeta
from .props import props
class SubclassWithMeta_Meta(InitSubclassMeta):
_meta = None
def __str__(cls):
if cls._meta:
return cls._meta.name
return cls.__name__
def __repr__(cls):
return "<{} meta={}>".format(cls.__name__, repr(cls._meta))
class SubclassWithMeta(six.with_metaclass(SubclassWithMeta_Meta)):
"""This class improves __init_subclass__ to receive automatically the options from meta"""
# We will only have the metaclass in Python 2
def __init_subclass__(cls, **meta_options):
"""This method just terminates the super() chain"""
_Meta = getattr(cls, "Meta", None)
_meta_props = {}
if _Meta:
if isinstance(_Meta, dict):
_meta_props = _Meta
elif isclass(_Meta):
_meta_props = props(_Meta)
else:
raise Exception(
"Meta have to be either a class or a dict. Received {}".format(
_Meta
)
)
delattr(cls, "Meta")
options = dict(meta_options, **_meta_props)
abstract = options.pop("abstract", False)
if abstract:
assert not options, (
"Abstract types can only contain the abstract attribute. "
"Received: abstract, {option_keys}"
).format(option_keys=", ".join(options.keys()))
else:
super_class = super(cls, cls)
if hasattr(super_class, "__init_subclass_with_meta__"):
super_class.__init_subclass_with_meta__(**options)
@classmethod
def __init_subclass_with_meta__(cls, **meta_options):
"""This method just terminates the super() chain"""
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