def _get_field_meta(cls, field: Field, schema_type: SchemaType) -> Tuple[FieldMeta, bool]:
required = True
field_meta = FieldMeta(schema_type=schema_type)
default_value = MISSING
if field.default is not MISSING:
# In case of default value given
default_value = field.default
elif field.default_factory is not MISSING and field.default_factory is not None: # type: ignore
# In case of a default factory given, we call it
default_value = field.default_factory() # type: ignore
if default_value is not MISSING:
field_meta.default = cls._encode_field(field.type, default_value, omit_none=False)
required = False
if field.metadata is not None:
if "examples" in field.metadata:
field_meta.examples = [
cls._encode_field(field.type, example, omit_none=False) for example in field.metadata["examples"]
]
if "extensions" in field.metadata:
field_meta.extensions = field.metadata["extensions"]
if "description" in field.metadata:
field_meta.description = field.metadata["description"]
if "title" in field.metadata:
field_meta.title = field.metadata["title"]
if schema_type == SchemaType.OPENAPI_3:
field_meta.read_only = field.metadata.get("read_only")
if field_meta.read_only and default_value is MISSING:
warnings.warn(f"Read-only fields should have a default value")
field_meta.write_only = field.metadata.get("write_only")
return field_meta, required
def get_dataclass_default(field: Field, omit_default: Optional[bool]) -> Any:
if not omit_default:
return MISSING
# type ignore because of https://github.com/python/mypy/issues/6910
if field.default_factory != MISSING: # type: ignore
return field.default_factory() # type: ignore
return field.default
def _get_field_meta(cls, field: Field,
schema_type: SchemaType) -> Tuple[FieldMeta, bool]:
required = True
field_meta = FieldMeta()
default_value = None
if field.default is not MISSING and field.default is not None:
# In case of default value given
default_value = field.default
elif field.default_factory is not MISSING and field.default_factory is not None: # type: ignore
# In case of a default factory given, we call it
default_value = field.default_factory() # type: ignore
if default_value is not None:
field_meta.default = cls._encode_field(field.type,
default_value,
omit_none=False)
required = False
if field.metadata is not None:
if "description" in field.metadata:
field_meta.description = field.metadata["description"]
if schema_type == SchemaType.OPENAPI_3:
field_meta.read_only = field.metadata.get("read_only")
if field_meta.read_only and default_value is None:
raise ValueError(
f"Read-only fields must have a default value")
field_meta.write_only = field.metadata.get("write_only")
return field_meta, required
def get_default(field: Field, schema: Schema[T]) -> Any:
if not schema.omit_default:
return MISSING
# type ignore because of https://github.com/python/mypy/issues/6910
if field.default_factory != MISSING: # type: ignore
return field.default_factory() # type: ignore
return field.default
def get_default_value_for_field(field: Field) -> Any:
if field.default != MISSING:
return field.default
elif field.default_factory != MISSING: # type: ignore
return field.default_factory() # type: ignore
elif is_optional(field.type):
return None
raise DefaultValueNotFoundError()
def _get_default_value_for_field(field: Field) -> Any:
if field.default != MISSING:
return field.default
elif field.default_factory != MISSING:
return field.default_factory()
elif _is_optional(field.type):
return None
else:
raise MissingValueError(field)
def _get_dataclass_field_default(field: Field) -> Any:
if field.default_factory is not MISSING:
# pyre-fixme[29]: `Union[dataclasses._MISSING_TYPE,
# dataclasses._DefaultFactory[typing.Any]]` is not a function.
return field.default_factory()
elif field.default is not MISSING:
return field.default
else:
return None
def _convert_dataclass_field(value, field: dataclasses.Field):
if value is not dataclasses.MISSING:
return convert(value, field.type)
if field.default is not dataclasses.MISSING:
return field.default
if field.default_factory is not dataclasses.MISSING:
return field.default_factory()
elif is_optional(field.type):
return None
else:
raise MissingException
def _get_field_default(field: dataclasses.Field):
"""
Return a marshmallow default value given a dataclass default value
>>> _get_field_default(dataclasses.field())
<marshmallow.missing>
"""
if field.default_factory is not dataclasses.MISSING:
return field.default_factory()
elif field.default is dataclasses.MISSING:
return marshmallow.missing
return field.default
def _default_value(x: Field):
"""Return the default value of the input Field.
Args:
x (Field): input Field.
Returns:
object: default value of the input Field.
"""
if x.default not in (MISSING, _MISSING):
return x.default
if x.default_factory not in (MISSING, _MISSING):
return x.default_factory()
return x.default
def _add_type_list(group: argparse._ArgumentGroup, field: dataclasses.Field,
name: str):
group.add_argument(
f"--{name}_{field.name}",
type=typing.get_args(field.type)[0],
default=None
if field.default_factory is dataclasses.MISSING # type: ignore
else field.default_factory(), # type: ignore
required=field.default_factory is dataclasses.MISSING, # type: ignore
choices=field.metadata.get( # type: ignore
Options.POSSIBLE_VALUES, Options.POSSIBLE_VALUES.value),
help=field.metadata.get(Options.HELP_TEXT,
Options.HELP_TEXT.value), # type: ignore
nargs="*",
)
def _get_value_for_field(field: Field, data: Data, config: Config) -> Any:
try:
if field.name in config.prefixed:
return _extract_nested_dict_for_prefix(config.prefixed[field.name],
data)
elif field.name in config.flattened:
return _extract_flattened_fields(field, data, config.remap)
else:
key_name = config.remap.get(field.name, field.name)
return data[key_name]
except KeyError:
if _is_optional(field.type):
return None
elif field.default != MISSING:
return field.default
elif field.default_factory != MISSING:
return field.default_factory()
else:
raise MissingValueError(field)
def _get_default(catch_all_field: Field) -> Any:
# access to the default factory currently causes
# a false-positive mypy error (16. Dec 2019):
# https://github.com/python/mypy/issues/6910
# noinspection PyProtectedMember
has_default = not isinstance(catch_all_field.default,
dataclasses._MISSING_TYPE)
# noinspection PyProtectedMember
has_default_factory = not isinstance(catch_all_field.default_factory,
# type: ignore
dataclasses._MISSING_TYPE)
default_value = _CatchAllUndefinedParameters._SentinelNoDefault
if has_default:
default_value = catch_all_field.default
elif has_default_factory:
# This might be unwanted if the default factory constructs
# something expensive,
# because we have to construct it again just for this test
default_value = catch_all_field.default_factory() # type: ignore
return default_value
def _get_field_meta(cls, field: Field,
schema_type: SchemaType) -> Tuple[FieldMeta, bool]:
required = True
field_meta = FieldMeta()
default_value = None
if field.default is not MISSING and field.default is not None:
# In case of default value given
default_value = field.default
elif field.default_factory is not MISSING and field.default_factory is not None: # type: ignore
# In case of a default factory given, we call it
default_value = field.default_factory() # type: ignore
if default_value is not None:
field_meta.default = cls._encode_field(field.type,
default_value,
omit_none=False)
required = False
if field.metadata is not None:
if "description" in field.metadata:
field_meta.description = field.metadata["description"]
return field_meta, required
def get_default(field: Field) -> Any:
if field.default_factory is not MISSING:
value = field.default_factory()
else:
value = field.default
return value if value is not MISSING else None
def colander_params(
prop: dataclasses.Field,
oid_prefix: str,
schema: type,
request: typing.Any,
mode=None,
**kwargs,
) -> dict:
"""
Get parameters for ``colander.SchemaNode`` constructor from ``dataclass.Field``
:param prop: ``dataclass.Field`` object
:param oid_prefix: string prefix for use as field oid
:param schema: ``dataclass`` based class
:param request: ``request`` object. Accepts anything, as it is merely passed to validators
:param mode: one of the following: ``'default'``, ``'edit'``, ``'edit-process'``
:param kwargs: additional parameters to be included into output. Will override derived parameters.
:return: dictionary of parameters for ``colander.SchemaNode``
"""
t = dataclass_get_type(prop)
default_value = None
if t["type"] == dict:
default_value = {}
elif t["type"] == list:
default_value = []
elif t["type"] == set:
default_value = set()
if (not isinstance(prop.default, dataclasses._MISSING_TYPE)
and prop.default is not None):
default_value = prop.default
elif (not isinstance(prop.default_factory, dataclasses._MISSING_TYPE)
and prop.default_factory is not None):
default_value = prop.default_factory()
params = {
"name": prop.name,
"oid": "%s-%s" % (oid_prefix, prop.name),
"missing": colander.required if t["required"] else default_value,
"default": default_value,
}
if "deform.widget" in prop.metadata.keys():
params["widget"] = copy.copy(prop.metadata["deform.widget"])
elif "deform.widget_factory" in prop.metadata.keys():
params["widget"] = prop.metadata["deform.widget_factory"](request)
validators = prop.metadata.get("validators", None)
if validators:
params["validator"] = ValidatorsWrapper(validators,
schema=schema,
request=request,
mode=mode)
preparers = prop.metadata.get("preparers", None)
if preparers:
params["preparer"] = PreparersWrapper(preparers,
schema=schema,
request=request,
mode=mode)
title = prop.metadata.get("title", None)
if title:
params["title"] = title
description = prop.metadata.get("description", None)
if description:
params["description"] = description
params.update(kwargs)
return params
def default_field_value(f: Field) -> Any:
if callable(f.default_factory): # type: ignore
return f.default_factory() # type: ignore
else:
return f.default
def get_dataclass_default(field: Field) -> Any:
# type ignore because of https://github.com/python/mypy/issues/6910
if field.default_factory != MISSING: # type: ignore
return field.default_factory() # type: ignore
return field.default
def _parse_dataclass_field(parser: ArgumentParser,
field: dataclasses.Field):
field_name = f"--{field.name}"
kwargs = field.metadata.copy()
# field.metadata is not used at all by Data Classes,
# it is provided as a third-party extension mechanism.
if isinstance(field.type, str):
raise RuntimeError(
"Unresolved type detected, which should have been done with the help of "
"`typing.get_type_hints` method by default")
origin_type = getattr(field.type, "__origin__", field.type)
if origin_type is Union:
if len(field.type.__args__) != 2 or type(
None) not in field.type.__args__:
raise ValueError(
"Only `Union[X, NoneType]` (i.e., `Optional[X]`) is allowed for `Union`"
)
if bool not in field.type.__args__:
# filter `NoneType` in Union (except for `Union[bool, NoneType]`)
field.type = (field.type.__args__[0] if isinstance(
None, field.type.__args__[1]) else field.type.__args__[1])
origin_type = getattr(field.type, "__origin__", field.type)
# A variable to store kwargs for a boolean field, if needed
# so that we can init a `no_*` complement argument (see below)
bool_kwargs = {}
if isinstance(field.type, type) and issubclass(field.type, Enum):
kwargs["choices"] = [x.value for x in field.type]
kwargs["type"] = type(kwargs["choices"][0])
if field.default is not dataclasses.MISSING:
kwargs["default"] = field.default
else:
kwargs["required"] = True
elif field.type is bool or field.type is Optional[bool]:
# Copy the currect kwargs to use to instantiate a `no_*` complement argument below.
# We do not initialize it here because the `no_*` alternative must be instantiated after the real argument
bool_kwargs = copy(kwargs)
# Hack because type=bool in argparse does not behave as we want.
kwargs["type"] = string_to_bool
if field.type is bool or (field.default is not None
and field.default
is not dataclasses.MISSING):
# Default value is False if we have no default when of type bool.
default = False if field.default is dataclasses.MISSING else field.default
# This is the value that will get picked if we don't include --field_name in any way
kwargs["default"] = default
# This tells argparse we accept 0 or 1 value after --field_name
kwargs["nargs"] = "?"
# This is the value that will get picked if we do --field_name (without value)
kwargs["const"] = True
elif isclass(origin_type) and issubclass(origin_type, list):
kwargs["type"] = field.type.__args__[0]
kwargs["nargs"] = "+"
if field.default_factory is not dataclasses.MISSING:
kwargs["default"] = field.default_factory()
elif field.default is dataclasses.MISSING:
kwargs["required"] = True
else:
kwargs["type"] = field.type
if field.default is not dataclasses.MISSING:
kwargs["default"] = field.default
elif field.default_factory is not dataclasses.MISSING:
kwargs["default"] = field.default_factory()
else:
kwargs["required"] = True
parser.add_argument(field_name, **kwargs)
# Add a complement `no_*` argument for a boolean field AFTER the initial field has already been added.
# Order is important for arguments with the same destination!
# We use a copy of earlier kwargs because the original kwargs have changed a lot before reaching down
# here and we do not need those changes/additional keys.
if field.default is True and (field.type is bool
or field.type is Optional[bool]):
bool_kwargs["default"] = False
parser.add_argument(f"--no_{field.name}",
action="store_false",
dest=field.name,
**bool_kwargs)
def has_default(self, field: dataclasses.Field) -> FieldDefault:
if field.default != dataclasses.MISSING:
return FieldDefault(True, field.default)
if field.default_factory != dataclasses.MISSING:
return FieldDefault(True, field.default_factory())
return FieldDefault()
