def modify_esteem(self, data, esteem_id=None):
"""Create or modify an esteem object according to the specified value."""
parsed_data = self._parse_xml_to_dict(data)
if esteem_id:
esteem = Esteem.objects.get(id=esteem_id)
else:
esteem = Esteem()
try:
user_id = self._get_id_from_atom_link(parsed_data['user'])
user = User.objects.get(id=user_id)
esteem.user = user
esteem.value = parsed_data['value']
esteem.save()
return esteem
except User.DoesNotExist:
raise InvalidDataException("The user provided does not exist (id: %s)"
% (user_id))
except KeyError, e:
raise InvalidDataException("The data sent was missing an attribute!")