def _del(self, obj, value=None):
old = self._get(obj)
try:
delattr(obj, self._name)
except AttributeError:
pass
else:
self.handle(AttributeUpdated(obj, self, old, self.default))
def _set(self, obj, value):
if value not in self.values:
raise AttributeError("Value should be one of %s" % str(self.values))
old = self._get(obj)
if value == old:
return
if value == self.default:
delattr(obj, self._name)
else:
setattr(obj, self._name, value)
self.handle(AttributeUpdated(obj, self, old, value))
def _set(self, obj, value):
if (value is not None and not isinstance(value, self.type)
and not isinstance(value, str)):
raise AttributeError(
"Value should be of type %s" % hasattr(self.type, "__name__")
and self.type.__name__ or self.type)
if value == self._get(obj):
return
old = self._get(obj)
if value == self.default and hasattr(obj, self._name):
delattr(obj, self._name)
else:
setattr(obj, self._name, value)
self.handle(AttributeUpdated(obj, self, old, value))
def unlink(self, obj):
old = self._get(obj)
self.handle(AttributeUpdated(obj, self, old, old))
def unlink(self, obj):
old = self._get(obj)
log.debug("Unlink attribute %s.%s", obj, self.name)
self.handle(AttributeUpdated(obj, self, old, old))