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bazarr/libs/flask_restx/fields.py

903 lines
27 KiB

import re
import fnmatch
import inspect
from calendar import timegm
from datetime import date, datetime
from decimal import Decimal, ROUND_HALF_EVEN
from email.utils import formatdate
from urllib.parse import urlparse, urlunparse
from flask import url_for, request
from werkzeug.utils import cached_property
from .inputs import (
date_from_iso8601,
datetime_from_iso8601,
datetime_from_rfc822,
boolean,
)
from .errors import RestError
from .marshalling import marshal
from .utils import camel_to_dash, not_none
__all__ = (
"Raw",
"String",
"FormattedString",
"Url",
"DateTime",
"Date",
"Boolean",
"Integer",
"Float",
"Arbitrary",
"Fixed",
"Nested",
"List",
"ClassName",
"Polymorph",
"Wildcard",
"StringMixin",
"MinMaxMixin",
"NumberMixin",
"MarshallingError",
)
class MarshallingError(RestError):
"""
This is an encapsulating Exception in case of marshalling error.
"""
def __init__(self, underlying_exception):
# just put the contextual representation of the error to hint on what
# went wrong without exposing internals
super(MarshallingError, self).__init__(str(underlying_exception))
def is_indexable_but_not_string(obj):
return not hasattr(obj, "strip") and hasattr(obj, "__iter__")
def is_integer_indexable(obj):
return isinstance(obj, list) or isinstance(obj, tuple)
def get_value(key, obj, default=None):
"""Helper for pulling a keyed value off various types of objects"""
if isinstance(key, int):
return _get_value_for_key(key, obj, default)
elif callable(key):
return key(obj)
else:
return _get_value_for_keys(key.split("."), obj, default)
def _get_value_for_keys(keys, obj, default):
if len(keys) == 1:
return _get_value_for_key(keys[0], obj, default)
else:
return _get_value_for_keys(
keys[1:], _get_value_for_key(keys[0], obj, default), default
)
def _get_value_for_key(key, obj, default):
if is_indexable_but_not_string(obj):
try:
return obj[key]
except (IndexError, TypeError, KeyError):
pass
if is_integer_indexable(obj):
try:
return obj[int(key)]
except (IndexError, TypeError, ValueError):
pass
return getattr(obj, key, default)
def to_marshallable_type(obj):
"""
Helper for converting an object to a dictionary only if it is not
dictionary already or an indexable object nor a simple type
"""
if obj is None:
return None # make it idempotent for None
if hasattr(obj, "__marshallable__"):
return obj.__marshallable__()
if hasattr(obj, "__getitem__"):
return obj # it is indexable it is ok
return dict(obj.__dict__)
class Raw(object):
"""
Raw provides a base field class from which others should extend. It
applies no formatting by default, and should only be used in cases where
data does not need to be formatted before being serialized. Fields should
throw a :class:`MarshallingError` in case of parsing problem.
:param default: The default value for the field, if no value is
specified.
:param attribute: If the public facing value differs from the internal
value, use this to retrieve a different attribute from the response
than the publicly named value.
:param str title: The field title (for documentation purpose)
:param str description: The field description (for documentation purpose)
:param bool required: Is the field required ?
:param bool readonly: Is the field read only ? (for documentation purpose)
:param example: An optional data example (for documentation purpose)
:param callable mask: An optional mask function to be applied to output
"""
#: The JSON/Swagger schema type
__schema_type__ = "object"
#: The JSON/Swagger schema format
__schema_format__ = None
#: An optional JSON/Swagger schema example
__schema_example__ = None
def __init__(
self,
default=None,
attribute=None,
title=None,
description=None,
required=None,
readonly=None,
example=None,
mask=None,
**kwargs
):
self.attribute = attribute
self.default = default
self.title = title
self.description = description
self.required = required
self.readonly = readonly
self.example = example if example is not None else self.__schema_example__
self.mask = mask
def format(self, value):
"""
Formats a field's value. No-op by default - field classes that
modify how the value of existing object keys should be presented should
override this and apply the appropriate formatting.
:param value: The value to format
:raises MarshallingError: In case of formatting problem
Ex::
class TitleCase(Raw):
def format(self, value):
return unicode(value).title()
"""
return value
def output(self, key, obj, **kwargs):
"""
Pulls the value for the given key from the object, applies the
field's formatting and returns the result. If the key is not found
in the object, returns the default value. Field classes that create
values which do not require the existence of the key in the object
should override this and return the desired value.
:raises MarshallingError: In case of formatting problem
"""
value = get_value(key if self.attribute is None else self.attribute, obj)
if value is None:
default = self._v("default")
return self.format(default) if default else default
try:
data = self.format(value)
except MarshallingError as e:
msg = 'Unable to marshal field "{0}" value "{1}": {2}'.format(
key, value, str(e)
)
raise MarshallingError(msg)
return self.mask.apply(data) if self.mask else data
def _v(self, key):
"""Helper for getting a value from attribute allowing callable"""
value = getattr(self, key)
return value() if callable(value) else value
@cached_property
def __schema__(self):
return not_none(self.schema())
def schema(self):
return {
"type": self.__schema_type__,
"format": self.__schema_format__,
"title": self.title,
"description": self.description,
"readOnly": self.readonly,
"default": self._v("default"),
"example": self.example,
}
class Nested(Raw):
"""
Allows you to nest one set of fields inside another.
See :ref:`nested-field` for more information
:param dict model: The model dictionary to nest
:param bool allow_null: Whether to return None instead of a dictionary
with null keys, if a nested dictionary has all-null keys
:param bool skip_none: Optional key will be used to eliminate inner fields
which value is None or the inner field's key not
exist in data
:param kwargs: If ``default`` keyword argument is present, a nested
dictionary will be marshaled as its value if nested dictionary is
all-null keys (e.g. lets you return an empty JSON object instead of
null)
"""
__schema_type__ = None
def __init__(
self, model, allow_null=False, skip_none=False, as_list=False, **kwargs
):
self.model = model
self.as_list = as_list
self.allow_null = allow_null
self.skip_none = skip_none
super(Nested, self).__init__(**kwargs)
@property
def nested(self):
return getattr(self.model, "resolved", self.model)
def output(self, key, obj, ordered=False, **kwargs):
value = get_value(key if self.attribute is None else self.attribute, obj)
if value is None:
if self.allow_null:
return None
elif self.default is not None:
return self.default
return marshal(value, self.nested, skip_none=self.skip_none, ordered=ordered)
def schema(self):
schema = super(Nested, self).schema()
ref = "#/definitions/{0}".format(self.nested.name)
if self.as_list:
schema["type"] = "array"
schema["items"] = {"$ref": ref}
elif any(schema.values()):
# There is already some properties in the schema
allOf = schema.get("allOf", [])
allOf.append({"$ref": ref})
schema["allOf"] = allOf
else:
schema["$ref"] = ref
return schema
def clone(self, mask=None):
kwargs = self.__dict__.copy()
model = kwargs.pop("model")
if mask:
model = mask.apply(model.resolved if hasattr(model, "resolved") else model)
return self.__class__(model, **kwargs)
class List(Raw):
"""
Field for marshalling lists of other fields.
See :ref:`list-field` for more information.
:param cls_or_instance: The field type the list will contain.
"""
def __init__(self, cls_or_instance, **kwargs):
self.min_items = kwargs.pop("min_items", None)
self.max_items = kwargs.pop("max_items", None)
self.unique = kwargs.pop("unique", None)
super(List, self).__init__(**kwargs)
error_msg = "The type of the list elements must be a subclass of fields.Raw"
if isinstance(cls_or_instance, type):
if not issubclass(cls_or_instance, Raw):
raise MarshallingError(error_msg)
self.container = cls_or_instance()
else:
if not isinstance(cls_or_instance, Raw):
raise MarshallingError(error_msg)
self.container = cls_or_instance
def format(self, value):
# Convert all instances in typed list to container type
if isinstance(value, set):
value = list(value)
is_nested = isinstance(self.container, Nested) or type(self.container) is Raw
def is_attr(val):
return self.container.attribute and hasattr(val, self.container.attribute)
if value is None:
return []
return [
self.container.output(
idx,
val
if (isinstance(val, dict) or is_attr(val)) and not is_nested
else value,
)
for idx, val in enumerate(value)
]
def output(self, key, data, ordered=False, **kwargs):
value = get_value(key if self.attribute is None else self.attribute, data)
# we cannot really test for external dict behavior
if is_indexable_but_not_string(value) and not isinstance(value, dict):
return self.format(value)
if value is None:
return self._v("default")
return [marshal(value, self.container.nested)]
def schema(self):
schema = super(List, self).schema()
schema.update(
minItems=self._v("min_items"),
maxItems=self._v("max_items"),
uniqueItems=self._v("unique"),
)
schema["type"] = "array"
schema["items"] = self.container.__schema__
return schema
def clone(self, mask=None):
kwargs = self.__dict__.copy()
model = kwargs.pop("container")
if mask:
model = mask.apply(model)
return self.__class__(model, **kwargs)
class StringMixin(object):
__schema_type__ = "string"
def __init__(self, *args, **kwargs):
self.min_length = kwargs.pop("min_length", None)
self.max_length = kwargs.pop("max_length", None)
self.pattern = kwargs.pop("pattern", None)
super(StringMixin, self).__init__(*args, **kwargs)
def schema(self):
schema = super(StringMixin, self).schema()
schema.update(
minLength=self._v("min_length"),
maxLength=self._v("max_length"),
pattern=self._v("pattern"),
)
return schema
class MinMaxMixin(object):
def __init__(self, *args, **kwargs):
self.minimum = kwargs.pop("min", None)
self.exclusiveMinimum = kwargs.pop("exclusiveMin", None)
self.maximum = kwargs.pop("max", None)
self.exclusiveMaximum = kwargs.pop("exclusiveMax", None)
super(MinMaxMixin, self).__init__(*args, **kwargs)
def schema(self):
schema = super(MinMaxMixin, self).schema()
schema.update(
minimum=self._v("minimum"),
exclusiveMinimum=self._v("exclusiveMinimum"),
maximum=self._v("maximum"),
exclusiveMaximum=self._v("exclusiveMaximum"),
)
return schema
class NumberMixin(MinMaxMixin):
__schema_type__ = "number"
def __init__(self, *args, **kwargs):
self.multiple = kwargs.pop("multiple", None)
super(NumberMixin, self).__init__(*args, **kwargs)
def schema(self):
schema = super(NumberMixin, self).schema()
schema.update(multipleOf=self._v("multiple"))
return schema
class String(StringMixin, Raw):
"""
Marshal a value as a string.
"""
def __init__(self, *args, **kwargs):
self.enum = kwargs.pop("enum", None)
self.discriminator = kwargs.pop("discriminator", None)
super(String, self).__init__(*args, **kwargs)
self.required = self.discriminator or self.required
def format(self, value):
try:
return str(value)
except ValueError as ve:
raise MarshallingError(ve)
def schema(self):
enum = self._v("enum")
schema = super(String, self).schema()
if enum:
schema.update(enum=enum)
if enum and schema["example"] is None:
schema["example"] = enum[0]
return schema
class Integer(NumberMixin, Raw):
"""
Field for outputting an integer value.
:param int default: The default value for the field, if no value is specified.
"""
__schema_type__ = "integer"
def format(self, value):
try:
if value is None:
return self.default
return int(value)
except (ValueError, TypeError) as ve:
raise MarshallingError(ve)
class Float(NumberMixin, Raw):
"""
A double as IEEE-754 double precision.
ex : 3.141592653589793 3.1415926535897933e-06 3.141592653589793e+24 nan inf -inf
"""
def format(self, value):
try:
if value is None:
return self.default
return float(value)
except (ValueError, TypeError) as ve:
raise MarshallingError(ve)
class Arbitrary(NumberMixin, Raw):
"""
A floating point number with an arbitrary precision.
ex: 634271127864378216478362784632784678324.23432
"""
def format(self, value):
return str(Decimal(value))
ZERO = Decimal()
class Fixed(NumberMixin, Raw):
"""
A decimal number with a fixed precision.
"""
def __init__(self, decimals=5, **kwargs):
super(Fixed, self).__init__(**kwargs)
self.precision = Decimal("0." + "0" * (decimals - 1) + "1")
def format(self, value):
dvalue = Decimal(value)
if not dvalue.is_normal() and dvalue != ZERO:
raise MarshallingError("Invalid Fixed precision number.")
return str(dvalue.quantize(self.precision, rounding=ROUND_HALF_EVEN))
class Boolean(Raw):
"""
Field for outputting a boolean value.
Empty collections such as ``""``, ``{}``, ``[]``, etc. will be converted to ``False``.
"""
__schema_type__ = "boolean"
def format(self, value):
return boolean(value)
class DateTime(MinMaxMixin, Raw):
"""
Return a formatted datetime string in UTC. Supported formats are RFC 822 and ISO 8601.
See :func:`email.utils.formatdate` for more info on the RFC 822 format.
See :meth:`datetime.datetime.isoformat` for more info on the ISO 8601 format.
:param str dt_format: ``rfc822`` or ``iso8601``
"""
__schema_type__ = "string"
__schema_format__ = "date-time"
def __init__(self, dt_format="iso8601", **kwargs):
super(DateTime, self).__init__(**kwargs)
self.dt_format = dt_format
def parse(self, value):
if value is None:
return None
elif isinstance(value, str):
parser = (
datetime_from_iso8601
if self.dt_format == "iso8601"
else datetime_from_rfc822
)
return parser(value)
elif isinstance(value, datetime):
return value
elif isinstance(value, date):
return datetime(value.year, value.month, value.day)
else:
raise ValueError("Unsupported DateTime format")
def format(self, value):
try:
value = self.parse(value)
if self.dt_format == "iso8601":
return self.format_iso8601(value)
elif self.dt_format == "rfc822":
return self.format_rfc822(value)
else:
raise MarshallingError("Unsupported date format %s" % self.dt_format)
except (AttributeError, ValueError) as e:
raise MarshallingError(e)
def format_rfc822(self, dt):
"""
Turn a datetime object into a formatted date.
:param datetime dt: The datetime to transform
:return: A RFC 822 formatted date string
"""
return formatdate(timegm(dt.utctimetuple()))
def format_iso8601(self, dt):
"""
Turn a datetime object into an ISO8601 formatted date.
:param datetime dt: The datetime to transform
:return: A ISO 8601 formatted date string
"""
return dt.isoformat()
def _for_schema(self, name):
value = self.parse(self._v(name))
return self.format(value) if value else None
def schema(self):
schema = super(DateTime, self).schema()
schema["default"] = self._for_schema("default")
schema["minimum"] = self._for_schema("minimum")
schema["maximum"] = self._for_schema("maximum")
return schema
class Date(DateTime):
"""
Return a formatted date string in UTC in ISO 8601.
See :meth:`datetime.date.isoformat` for more info on the ISO 8601 format.
"""
__schema_format__ = "date"
def __init__(self, **kwargs):
kwargs.pop("dt_format", None)
super(Date, self).__init__(dt_format="iso8601", **kwargs)
def parse(self, value):
if value is None:
return None
elif isinstance(value, str):
return date_from_iso8601(value)
elif isinstance(value, datetime):
return value.date()
elif isinstance(value, date):
return value
else:
raise ValueError("Unsupported Date format")
class Url(StringMixin, Raw):
"""
A string representation of a Url
:param str endpoint: Endpoint name. If endpoint is ``None``, ``request.endpoint`` is used instead
:param bool absolute: If ``True``, ensures that the generated urls will have the hostname included
:param str scheme: URL scheme specifier (e.g. ``http``, ``https``)
"""
def __init__(self, endpoint=None, absolute=False, scheme=None, **kwargs):
super(Url, self).__init__(**kwargs)
self.endpoint = endpoint
self.absolute = absolute
self.scheme = scheme
def output(self, key, obj, **kwargs):
try:
data = to_marshallable_type(obj)
endpoint = self.endpoint if self.endpoint is not None else request.endpoint
o = urlparse(url_for(endpoint, _external=self.absolute, **data))
if self.absolute:
scheme = self.scheme if self.scheme is not None else o.scheme
return urlunparse((scheme, o.netloc, o.path, "", "", ""))
return urlunparse(("", "", o.path, "", "", ""))
except TypeError as te:
raise MarshallingError(te)
class FormattedString(StringMixin, Raw):
"""
FormattedString is used to interpolate other values from
the response into this field. The syntax for the source string is
the same as the string :meth:`~str.format` method from the python
stdlib.
Ex::
fields = {
'name': fields.String,
'greeting': fields.FormattedString("Hello {name}")
}
data = {
'name': 'Doug',
}
marshal(data, fields)
:param str src_str: the string to format with the other values from the response.
"""
def __init__(self, src_str, **kwargs):
super(FormattedString, self).__init__(**kwargs)
self.src_str = str(src_str)
def output(self, key, obj, **kwargs):
try:
data = to_marshallable_type(obj)
return self.src_str.format(**data)
except (TypeError, IndexError) as error:
raise MarshallingError(error)
class ClassName(String):
"""
Return the serialized object class name as string.
:param bool dash: If `True`, transform CamelCase to kebab_case.
"""
def __init__(self, dash=False, **kwargs):
super(ClassName, self).__init__(**kwargs)
self.dash = dash
def output(self, key, obj, **kwargs):
classname = obj.__class__.__name__
if classname == "dict":
return "object"
return camel_to_dash(classname) if self.dash else classname
class Polymorph(Nested):
"""
A Nested field handling inheritance.
Allows you to specify a mapping between Python classes and fields specifications.
.. code-block:: python
mapping = {
Child1: child1_fields,
Child2: child2_fields,
}
fields = api.model('Thing', {
owner: fields.Polymorph(mapping)
})
:param dict mapping: Maps classes to their model/fields representation
"""
def __init__(self, mapping, required=False, **kwargs):
self.mapping = mapping
parent = self.resolve_ancestor(list(mapping.values()))
super(Polymorph, self).__init__(parent, allow_null=not required, **kwargs)
def output(self, key, obj, ordered=False, **kwargs):
# Copied from upstream NestedField
value = get_value(key if self.attribute is None else self.attribute, obj)
if value is None:
if self.allow_null:
return None
elif self.default is not None:
return self.default
# Handle mappings
if not hasattr(value, "__class__"):
raise ValueError("Polymorph field only accept class instances")
candidates = [
fields for cls, fields in self.mapping.items() if type(value) == cls
]
if len(candidates) <= 0:
raise ValueError("Unknown class: " + value.__class__.__name__)
elif len(candidates) > 1:
raise ValueError(
"Unable to determine a candidate for: " + value.__class__.__name__
)
else:
return marshal(
value, candidates[0].resolved, mask=self.mask, ordered=ordered
)
def resolve_ancestor(self, models):
"""
Resolve the common ancestor for all models.
Assume there is only one common ancestor.
"""
ancestors = [m.ancestors for m in models]
candidates = set.intersection(*ancestors)
if len(candidates) != 1:
field_names = [f.name for f in models]
raise ValueError(
"Unable to determine the common ancestor for: " + ", ".join(field_names)
)
parent_name = candidates.pop()
return models[0].get_parent(parent_name)
def clone(self, mask=None):
data = self.__dict__.copy()
mapping = data.pop("mapping")
for field in ("allow_null", "model"):
data.pop(field, None)
data["mask"] = mask
return Polymorph(mapping, **data)
class Wildcard(Raw):
"""
Field for marshalling list of "unkown" fields.
:param cls_or_instance: The field type the list will contain.
"""
exclude = set()
# cache the flat object
_flat = None
_obj = None
_cache = set()
_last = None
def __init__(self, cls_or_instance, **kwargs):
super(Wildcard, self).__init__(**kwargs)
error_msg = "The type of the wildcard elements must be a subclass of fields.Raw"
if isinstance(cls_or_instance, type):
if not issubclass(cls_or_instance, Raw):
raise MarshallingError(error_msg)
self.container = cls_or_instance()
else:
if not isinstance(cls_or_instance, Raw):
raise MarshallingError(error_msg)
self.container = cls_or_instance
def _flatten(self, obj):
if obj is None:
return None
if obj == self._obj and self._flat is not None:
return self._flat
if isinstance(obj, dict):
self._flat = [x for x in obj.items()]
else:
def __match_attributes(attribute):
attr_name, attr_obj = attribute
if inspect.isroutine(attr_obj) or (
attr_name.startswith("__") and attr_name.endswith("__")
):
return False
return True
attributes = inspect.getmembers(obj)
self._flat = [x for x in attributes if __match_attributes(x)]
self._cache = set()
self._obj = obj
return self._flat
@property
def key(self):
return self._last
def reset(self):
self.exclude = set()
self._flat = None
self._obj = None
self._cache = set()
self._last = None
def output(self, key, obj, ordered=False):
value = None
reg = fnmatch.translate(key)
if self._flatten(obj):
while True:
try:
# we are using pop() so that we don't
# loop over the whole object every time dropping the
# complexity to O(n)
if ordered:
# Get first element if respecting order
(objkey, val) = self._flat.pop(0)
else:
# Previous default retained
(objkey, val) = self._flat.pop()
if (
objkey not in self._cache
and objkey not in self.exclude
and re.match(reg, objkey, re.IGNORECASE)
):
value = val
self._cache.add(objkey)
self._last = objkey
break
except IndexError:
break
if value is None:
if self.default is not None:
return self.container.format(self.default)
return None
if isinstance(self.container, Nested):
return marshal(
value,
self.container.nested,
skip_none=self.container.skip_none,
ordered=ordered,
)
return self.container.format(value)
def schema(self):
schema = super(Wildcard, self).schema()
schema["type"] = "object"
schema["additionalProperties"] = self.container.__schema__
return schema
def clone(self):
kwargs = self.__dict__.copy()
model = kwargs.pop("container")
return self.__class__(model, **kwargs)