def test_format_to_tuple(value, expected_result, fails):
if not fails:
result = format_to_tuple(value)
assert result == expected_result
else:
with pytest.raises(InvalidFormatError):
result = format_to_tuple(value)
def get_default_serializer(class_attribute=None, format=None, value=None):
"""Retrieve the default ``on_serialize`` function that applies to the data
type of ``class_attribute``.
.. note::
If ``class_attribute`` does not have a SQLAlchemy data type, then
determines the data type based on ``value``.
:param class_attribute: The class attribute whose default serializer will be
returned. Defaults to :obj:`None <python:None>`.
:param format: The format to which the value should be serialized. Accepts
either: ``csv``, ``json``, ``yaml``, or ``dict``. Defaults to :obj:`None <python:None>`.
:type format: :class:`str <python:str>`
:param value: The class attribute's value.
:returns: The default :term:`serializer function` to apply or :obj:`None <python:None>`
:rtype: callable / :obj:`None <python:None>`
:raises InvalidFormatError: if ``format`` is not a valid format type
"""
format_to_tuple(format)
format = format.lower()
class_type_key = get_class_type_key(class_attribute, value)
serializer_dict = DEFAULT_SERIALIZERS.get(class_type_key, None)
if serializer_dict is None:
return None
return serializer_dict.get(format, None)
def _get_deserialized_value(cls,
value,
format,
attribute,
config_set=None,
**kwargs):
"""Retrieve the value of ``attribute`` after applying the attribute's
``on_deserialize`` function for the format indicated by ``format``.
:param value: The input value that was received when de-serializing.
:param format: The format to which the value should be serialized. Accepts
either: ``csv``, ``json``, ``yaml``, or ``dict``.
:type format: :class:`str <python:str>`
:param attribute: The name of the attribute that whose serialized value
should be returned.
:type attribute: :class:`str <python:str>`
:param config_set: If not :obj:`None <python:None>`, the named configuration set
whose configuration should be used to determine the deserialized value. Defaults
to :obj:`None <python:None>`.
:type config_set: :class:`str <python:str>` / :obj:`None <python:None>`
:returns: The value returned by the attribute's ``on_serialize`` function
for the indicated ``format``.
:raises InvalidFormatError: if ``format`` is not ``csv``, ``json``, ``yaml``,
or ``dict``.
:raises ValueDeserializationError: if the ``on_deserialize`` function raises
an exception
"""
# pylint: disable=line-too-long
from_csv, from_json, from_yaml, from_dict = format_to_tuple(format)
try:
supports_deserialization = cls.does_support_serialization(
attribute,
from_csv=from_csv,
from_json=from_json,
from_yaml=from_yaml,
from_dict=from_dict,
config_set=config_set)
except UnsupportedSerializationError:
supports_deserialization = False
if inspect_.isclass(cls):
class_name = str(cls)
class_obj = cls
else:
class_name = str(type(cls))
class_obj = cls.__class__
if not supports_deserialization:
raise UnsupportedDeserializationError(
"%s attribute '%s' does not support de-serialization from '%s'" % \
(class_name,
attribute,
format)
)
config = cls.get_attribute_serialization_config(attribute,
config_set=config_set)
on_deserialize = config.on_deserialize[format]
if on_deserialize is None:
on_deserialize = get_default_deserializer(getattr(
class_obj, config.name),
format=format)
if on_deserialize is None:
item = getattr(class_obj, config.name)
class_resolver = getattr(getattr(item, 'property', None),
'argument', None)
if class_resolver:
resolved_class = class_resolver()
else:
resolved_class = None
if resolved_class:
# pylint: disable=W0212
if hasattr(
resolved_class,
'new_from_json') and format == 'json' and isinstance(
value, dict):
as_json = json.dumps(value)
return_value = resolved_class.new_from_json(
as_json, **kwargs)
elif hasattr(
resolved_class,
'new_from_yaml') and format == 'yaml' and isinstance(
value, dict):
as_yaml = yaml.dump(value)
return_value = resolved_class.new_from_yaml(
value, **kwargs)
elif hasattr(
resolved_class,
'new_from_dict') and format == 'dict' and isinstance(
value, dict):
return_value = resolved_class.new_from_dict(
value, **kwargs)
else:
return_value = [
resolved_class(
**resolved_class._parse_dict(x, format, **kwargs))
for x in value
]
#pylint: enable=W0212
else:
return_value = value
else:
try:
return_value = on_deserialize(value)
except Exception:
raise ValueDeserializationError(
"attribute '%s' failed de-serialization to format '%s'" %
(attribute, format))
return return_value
def _get_serialized_value(self, format, attribute, config_set=None):
"""Retrieve the value of ``attribute`` after applying the attribute's
``on_serialize`` function for the format indicated by ``format``.
:param format: The format to which the value should be serialized. Accepts
either: ``csv``, ``json``, ``yaml``, or ``dict``.
:type format: :class:`str <python:str>`
:param attribute: The name of the attribute that whose serialized value
should be returned.
:type attribute: :class:`str <python:str>`
:param config_set: The name of the named configuration set whose configuration
should be used to retrieve the serialized value. Defaults to
:obj:`None <python:None>`.
:type config_set: :class:`str <python:str>` / :obj:`None <python:None>`
:returns: The value returned by the attribute's ``on_serialize`` function
for the indicated ``format``.
:raises InvalidFormatError: if ``format`` is not ``csv``, ``json``, ``yaml``,
or ``dict``.
:raises ValueSerializationError: if the ``on_serialize`` function raises
an exception
"""
# pylint: disable=line-too-long
to_csv, to_json, to_yaml, to_dict = format_to_tuple(format)
supports_serialization = self.does_support_serialization(
attribute,
to_csv=to_csv,
to_json=to_json,
to_yaml=to_yaml,
to_dict=to_dict,
config_set=config_set)
if not supports_serialization:
raise UnsupportedSerializationError(
"%s attribute '%s' does not support serialization to '%s'" %
(self.__class__, attribute, format))
config = self.get_attribute_serialization_config(attribute,
config_set=config_set)
on_serialize = config.on_serialize[format]
if on_serialize is None:
on_serialize = get_default_serializer(
getattr(self.__class__, attribute),
format=format,
value=getattr(self, attribute, None))
if on_serialize is None:
if format == 'csv':
return getattr(self, attribute, '')
return getattr(self, attribute, None)
try:
return_value = on_serialize(getattr(self, attribute, None))
except Exception:
raise ValueSerializationError(
"attribute '%s' failed serialization to format '%s'" %
(attribute, format))
return return_value