import inspect
import logging
from collections import OrderedDict
from django.db import models
from django.utils.encoding import force_text
from rest_framework import serializers, status
from rest_framework.mixins import DestroyModelMixin, RetrieveModelMixin, UpdateModelMixin
from rest_framework.request import is_form_media_type
from rest_framework.settings import api_settings as rest_framework_settings
from rest_framework.utils import encoders, json
from rest_framework.views import APIView
from drf_yasg.app_settings import swagger_settings
logger = logging.getLogger(__name__)
[docs]class no_body(object):
"""Used as a sentinel value to forcibly remove the body of a request via :func:`.swagger_auto_schema`."""
pass
[docs]class unset(object):
"""Used as a sentinel value for function parameters not set by the caller where ``None`` would be a valid value."""
pass
[docs]def swagger_auto_schema(method=None, methods=None, auto_schema=unset, request_body=None, query_serializer=None,
manual_parameters=None, operation_id=None, operation_description=None, operation_summary=None,
security=None, deprecated=None, responses=None, field_inspectors=None, filter_inspectors=None,
paginator_inspectors=None, **extra_overrides):
"""Decorate a view method to customize the :class:`.Operation` object generated from it.
`method` and `methods` are mutually exclusive and must only be present when decorating a view method that accepts
more than one HTTP request method.
The `auto_schema` and `operation_description` arguments take precendence over view- or method-level values.
:param str method: for multi-method views, the http method the options should apply to
:param list[str] methods: for multi-method views, the http methods the options should apply to
:param .inspectors.SwaggerAutoSchema auto_schema: custom class to use for generating the Operation object;
this overrides both the class-level ``swagger_schema`` attribute and the ``DEFAULT_AUTO_SCHEMA_CLASS``
setting, and can be set to ``None`` to prevent this operation from being generated
:param .Schema,.SchemaRef,.Serializer request_body: custom request body, or :class:`.no_body`. The value given here
will be used as the ``schema`` property of a :class:`.Parameter` with ``in: 'body'``.
A Schema or SchemaRef is not valid if this request consumes form-data, because ``form`` and ``body`` parameters
are mutually exclusive in an :class:`.Operation`. If you need to set custom ``form`` parameters, you can use
the `manual_parameters` argument.
If a ``Serializer`` class or instance is given, it will be automatically converted into a :class:`.Schema`
used as a ``body`` :class:`.Parameter`, or into a list of ``form`` :class:`.Parameter`\ s, as appropriate.
:param .Serializer query_serializer: if you use a ``Serializer`` to parse query parameters, you can pass it here
and have :class:`.Parameter` objects be generated automatically from it.
If any ``Field`` on the serializer cannot be represented as a ``query`` :class:`.Parameter`
(e.g. nested Serializers, file fields, ...), the schema generation will fail with an error.
Schema generation will also fail if the name of any Field on the `query_serializer` conflicts with parameters
generated by ``filter_backends`` or ``paginator``.
:param list[.Parameter] manual_parameters: a list of manual parameters to override the automatically generated ones
:class:`.Parameter`\ s are identified by their (``name``, ``in``) combination, and any parameters given
here will fully override automatically generated parameters if they collide.
It is an error to supply ``form`` parameters when the request does not consume form-data.
:param str operation_id: operation ID override; the operation ID must be unique accross the whole API
:param str operation_description: operation description override
:param str operation_summary: operation summary string
:param list[dict] security: security requirements override; used to specify which authetication mechanism
is requried to call this API; an empty list marks the endpoint as unauthenticated (i.e. removes all accepted
authentication schemes), and ``None`` will inherit the top-level secuirty requirements
:param bool deprecated: deprecation status for operation
:param dict[str,(.Schema,.SchemaRef,.Response,str,Serializer)] responses: a dict of documented manual responses
keyed on response status code. If no success (``2xx``) response is given, one will automatically be
generated from the request body and http method. If any ``2xx`` response is given the automatic response is
suppressed.
* if a plain string is given as value, a :class:`.Response` with no body and that string as its description
will be generated
* if ``None`` is given as a value, the response is ignored; this is mainly useful for disabling default
2xx responses, i.e. ``responses={200: None, 302: 'something'}``
* if a :class:`.Schema`, :class:`.SchemaRef` is given, a :class:`.Response` with the schema as its body and
an empty description will be generated
* a ``Serializer`` class or instance will be converted into a :class:`.Schema` and treated as above
* a :class:`.Response` object will be used as-is; however if its ``schema`` attribute is a ``Serializer``,
it will automatically be converted into a :class:`.Schema`
:param list[.FieldInspector] field_inspectors: extra serializer and field inspectors; these will be tried
before :attr:`.ViewInspector.field_inspectors` on the :class:`.inspectors.SwaggerAutoSchema` instance
:param list[.FilterInspector] filter_inspectors: extra filter inspectors; these will be tried before
:attr:`.ViewInspector.filter_inspectors` on the :class:`.inspectors.SwaggerAutoSchema` instance
:param list[.PaginatorInspector] paginator_inspectors: extra paginator inspectors; these will be tried before
:attr:`.ViewInspector.paginator_inspectors` on the :class:`.inspectors.SwaggerAutoSchema` instance
:param extra_overrides: extra values that will be saved into the ``overrides`` dict; these values will be available
in the handling :class:`.inspectors.SwaggerAutoSchema` instance via ``self.overrides``
"""
def decorator(view_method):
assert not any(hm in extra_overrides for hm in APIView.http_method_names), "HTTP method names not allowed here"
data = {
'request_body': request_body,
'query_serializer': query_serializer,
'manual_parameters': manual_parameters,
'operation_id': operation_id,
'operation_description': operation_description,
'security': security,
'responses': responses,
'filter_inspectors': list(filter_inspectors) if filter_inspectors else None,
'paginator_inspectors': list(paginator_inspectors) if paginator_inspectors else None,
'field_inspectors': list(field_inspectors) if field_inspectors else None,
}
data = filter_none(data)
if auto_schema is not unset:
data['auto_schema'] = auto_schema
data.update(extra_overrides)
if not data: # pragma: no cover
# no overrides to set, no use in doing more work
return
# if the method is an @action, it will have a bind_to_methods attribute, or a mapping attribute for drf>3.8
bind_to_methods = getattr(view_method, 'bind_to_methods', [])
mapping = getattr(view_method, 'mapping', {})
mapping_methods = [mth for mth, name in mapping.items() if name == view_method.__name__]
action_http_methods = bind_to_methods + mapping_methods
# if the method is actually a function based view (@api_view), it will have a 'cls' attribute
view_cls = getattr(view_method, 'cls', None)
api_view_http_methods = [m for m in getattr(view_cls, 'http_method_names', []) if hasattr(view_cls, m)]
available_http_methods = api_view_http_methods + action_http_methods
existing_data = getattr(view_method, '_swagger_auto_schema', {})
_methods = methods
if methods or method:
assert available_http_methods, "`method` or `methods` can only be specified on @action or @api_view views"
assert bool(methods) != bool(method), "specify either method or methods"
assert not isinstance(methods, str), "`methods` expects to receive a list of methods;" \
" use `method` for a single argument"
if method:
_methods = [method.lower()]
else:
_methods = [mth.lower() for mth in methods]
assert all(mth in available_http_methods for mth in _methods), "http method not bound to view"
assert not any(mth in existing_data for mth in _methods), "http method defined multiple times"
if available_http_methods:
# action or api_view
assert bool(api_view_http_methods) != bool(action_http_methods), "this should never happen"
if len(available_http_methods) > 1:
assert _methods, \
"on multi-method api_view, action, detail_route or list_route, you must specify " \
"swagger_auto_schema on a per-method basis using one of the `method` or `methods` arguments"
else:
# for a single-method view we assume that single method as the decorator target
_methods = _methods or available_http_methods
assert not any(hasattr(getattr(view_cls, mth, None), '_swagger_auto_schema') for mth in _methods), \
"swagger_auto_schema applied twice to method"
assert not any(mth in existing_data for mth in _methods), "swagger_auto_schema applied twice to method"
existing_data.update((mth.lower(), data) for mth in _methods)
view_method._swagger_auto_schema = existing_data
else:
assert not _methods, \
"the methods argument should only be specified when decorating an action, detail_route or " \
"list_route; you should also ensure that you put the swagger_auto_schema decorator " \
"AFTER (above) the _route decorator"
assert not existing_data, "swagger_auto_schema applied twice to method"
view_method._swagger_auto_schema = data
return view_method
return decorator
[docs]def swagger_serializer_method(serializer_or_field):
"""
Decorates the method of a serializers.SerializerMethodField
to hint as to how Swagger should be generated for this field.
:param serializer_or_field: ``Serializer``/``Field`` class or instance
:return:
"""
def decorator(serializer_method):
# stash the serializer for SerializerMethodFieldInspector to find
serializer_method._swagger_serializer = serializer_or_field
return serializer_method
return decorator
[docs]def is_list_view(path, method, view):
"""Check if the given path/method appears to represent a list view (as opposed to a detail/instance view).
:param str path: view path
:param str method: http method
:param APIView view: target view
:rtype: bool
"""
# for ViewSets, it could be the default 'list' action, or a list_route
action = getattr(view, 'action', '')
method = getattr(view, action, None)
detail = getattr(method, 'detail', None)
suffix = getattr(view, 'suffix', None)
if action in ('list', 'create') or detail is False or suffix == 'List':
return True
if action in ('retrieve', 'update', 'partial_update', 'destroy') or detail is True or suffix == 'Instance':
# a detail action is surely not a list route
return False
# for GenericAPIView, if it's a detail view it can't also be a list view
if isinstance(view, (RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin)):
return False
# if the last component in the path is parameterized it's probably not a list view
path_components = path.strip('/').split('/')
if path_components and '{' in path_components[-1]:
return False
# otherwise assume it's a list view
return True
[docs]def guess_response_status(method):
if method == 'post':
return status.HTTP_201_CREATED
elif method == 'delete':
return status.HTTP_204_NO_CONTENT
else:
return status.HTTP_200_OK
[docs]def param_list_to_odict(parameters):
"""Transform a list of :class:`.Parameter` objects into an ``OrderedDict`` keyed on the ``(name, in_)`` tuple of
each parameter.
Raises an ``AssertionError`` if `parameters` contains duplicate parameters (by their name + in combination).
:param list[.Parameter] parameters: the list of parameters
:return: `parameters` keyed by ``(name, in_)``
:rtype: dict[tuple(str,str),.Parameter]
"""
result = OrderedDict(((param.name, param.in_), param) for param in parameters)
assert len(result) == len(parameters), "duplicate Parameters found"
return result
[docs]def filter_none(obj):
"""Remove ``None`` values from tuples, lists or dictionaries. Return other objects as-is.
:param obj:
:return: collection with ``None`` values removed
"""
if obj is None:
return None
new_obj = None
if isinstance(obj, dict):
new_obj = type(obj)((k, v) for k, v in obj.items() if k is not None and v is not None)
if isinstance(obj, (list, tuple)):
new_obj = type(obj)(v for v in obj if v is not None)
if new_obj is not None and len(new_obj) != len(obj):
return new_obj # pragma: no cover
return obj
[docs]def force_serializer_instance(serializer):
"""Force `serializer` into a ``Serializer`` instance. If it is not a ``Serializer`` class or instance, raises
an assertion error.
:param serializer: serializer class or instance
:return: serializer instance
:rtype: serializers.BaseSerializer
"""
if inspect.isclass(serializer):
assert issubclass(serializer, serializers.BaseSerializer), "Serializer required, not %s" % serializer.__name__
return serializer()
assert isinstance(serializer, serializers.BaseSerializer), \
"Serializer class or instance required, not %s" % type(serializer).__name__
return serializer
[docs]def get_serializer_class(serializer):
"""Given a ``Serializer`` class or intance, return the ``Serializer`` class. If `serializer` is not a ``Serializer``
class or instance, raises an assertion error.
:param serializer: serializer class or instance, or ``None``
:return: serializer class
:rtype: type[serializers.BaseSerializer]
"""
if serializer is None:
return None
if inspect.isclass(serializer):
assert issubclass(serializer, serializers.BaseSerializer), "Serializer required, not %s" % serializer.__name__
return serializer
assert isinstance(serializer, serializers.BaseSerializer), \
"Serializer class or instance required, not %s" % type(serializer).__name__
return type(serializer)
[docs]def get_consumes(parser_classes):
"""Extract ``consumes`` MIME types from a list of parser classes.
:param list parser_classes: parser classes
:return: MIME types for ``consumes``
:rtype: list[str]
"""
media_types = [parser.media_type for parser in parser_classes or []]
if all(is_form_media_type(encoding) for encoding in media_types):
return media_types
else:
media_types = [encoding for encoding in media_types if not is_form_media_type(encoding)]
return media_types
[docs]def get_produces(renderer_classes):
"""Extract ``produces`` MIME types from a list of renderer classes.
:param list renderer_classes: renderer classes
:return: MIME types for ``produces``
:rtype: list[str]
"""
media_types = [renderer.media_type for renderer in renderer_classes or []]
media_types = [encoding for encoding in media_types
if not any(excluded in encoding for excluded in swagger_settings.EXCLUDED_MEDIA_TYPES)]
return media_types
[docs]def decimal_as_float(field):
"""
Returns true if ``field`` is a django-rest-framework DecimalField and its ``coerce_to_string`` attribute or the
``COERCE_DECIMAL_TO_STRING`` setting is set to ``False``.
:rtype: bool
"""
if isinstance(field, serializers.DecimalField) or isinstance(field, models.DecimalField):
return not getattr(field, 'coerce_to_string', rest_framework_settings.COERCE_DECIMAL_TO_STRING)
return False
[docs]def get_serializer_ref_name(serializer):
"""
Get serializer's ref_name (or None for ModelSerializer if it is named 'NestedSerializer')
:param serializer: Serializer instance
:return: Serializer's ``ref_name`` or ``None`` for inline serializer
:rtype: str
"""
serializer_meta = getattr(serializer, 'Meta', None)
serializer_name = type(serializer).__name__
if hasattr(serializer_meta, 'ref_name'):
ref_name = serializer_meta.ref_name
elif serializer_name == 'NestedSerializer' and isinstance(serializer, serializers.ModelSerializer):
logger.debug("Forcing inline output for ModelSerializer named 'NestedSerializer':\n" + str(serializer))
ref_name = None
else:
ref_name = serializer_name
if ref_name.endswith('Serializer'):
ref_name = ref_name[:-len('Serializer')]
return ref_name
[docs]def force_real_str(s, encoding='utf-8', strings_only=False, errors='strict'):
"""
Force `s` into a ``str`` instance.
Fix for https://github.com/axnsan12/drf-yasg/issues/159
"""
if s is not None:
s = force_text(s, encoding, strings_only, errors)
if type(s) != str:
s = '' + s
return s
[docs]def get_field_default(field):
"""
Get the default value for a field, converted to a JSON-compatible value while properly handling callables.
:param field: field instance
:return: default value
"""
default = getattr(field, 'default', serializers.empty)
if default is not serializers.empty:
if callable(default):
try:
if hasattr(default, 'set_context'):
default.set_context(field)
default = default()
except Exception: # pragma: no cover
logger.warning("default for %s is callable but it raised an exception when "
"called; 'default' will not be set on schema", field, exc_info=True)
default = serializers.empty
if default is not serializers.empty:
try:
default = field.to_representation(default)
# JSON roundtrip ensures that the value is valid JSON;
# for example, sets and tuples get transformed into lists
default = json.loads(json.dumps(default, cls=encoders.JSONEncoder))
if decimal_as_float(field):
default = float(default)
except Exception: # pragma: no cover
logger.warning("'default' on schema for %s will not be set because "
"to_representation raised an exception", field, exc_info=True)
default = serializers.empty
return default