from collections import defaultdict, OrderedDict
import django.db.models
import uritemplate
from coreapi.compat import force_text
from rest_framework.schemas.generators import SchemaGenerator
from rest_framework.schemas.inspectors import get_pk_description
from . import openapi
from .inspectors import SwaggerAutoSchema
from .openapi import ReferenceResolver
[docs]class OpenAPISchemaGenerator(object):
"""
This class iterates over all registered API endpoints and returns an appropriate OpenAPI 2.0 compliant schema.
Method implementations shamelessly stolen and adapted from rest_framework SchemaGenerator.
"""
def __init__(self, info, version, url=None, patterns=None, urlconf=None):
"""
:param .Info info: information about the API
:param str version: API version string, takes preedence over the version in `info`
:param str url: API
:param patterns: if given, only these patterns will be enumerated for inclusion in the API spec
:param urlconf: if patterns is not given, use this urlconf to enumerate patterns;
if not given, the default urlconf is used
"""
self._gen = SchemaGenerator(info.title, url, info.get('description', ''), patterns, urlconf)
self.info = info
self.version = version
[docs] def get_schema(self, request=None, public=False):
"""Generate an :class:`.Swagger` representing the API schema.
:param rest_framework.request.Request request: the request used for filtering
accesible endpoints and finding the spec URI
:param bool public: if True, all endpoints are included regardless of access through `request`
:return: the generated Swagger specification
:rtype: openapi.Swagger
"""
endpoints = self.get_endpoints(None if public else request)
components = ReferenceResolver(openapi.SCHEMA_DEFINITIONS)
paths = self.get_paths(endpoints, components)
url = self._gen.url
if not url and request is not None:
url = request.build_absolute_uri()
return openapi.Swagger(
info=self.info, paths=paths,
_url=url, _version=self.version, **dict(components)
)
[docs] def create_view(self, callback, method, request=None):
"""Create a view instance from a view callback as registered in urlpatterns.
:param callable callback: view callback registered in urlpatterns
:param str method: HTTP method
:param rest_framework.request.Request request: request to bind to the view
:return: the view instance
"""
view = self._gen.create_view(callback, method, request)
overrides = getattr(callback, 'swagger_auto_schema', None)
if overrides is not None:
# decorated function based view must have its decorator information passed on to the re-instantiated view
for method, _ in overrides.items():
view_method = getattr(view, method, None)
if view_method is not None: # pragma: no cover
setattr(view_method.__func__, 'swagger_auto_schema', overrides)
return view
[docs] def get_endpoints(self, request=None):
"""Iterate over all the registered endpoints in the API.
:param rest_framework.request.Request request: used for returning only endpoints available to the given request
:return: {path: (view_class, list[(http_method, view_instance)])
:rtype: dict
"""
inspector = self._gen.endpoint_inspector_cls(self._gen.patterns, self._gen.urlconf)
endpoints = inspector.get_api_endpoints()
view_paths = defaultdict(list)
view_cls = {}
for path, method, callback in endpoints:
view = self.create_view(callback, method, request)
path = self._gen.coerce_path(path, method, view)
view_paths[path].append((method, view))
view_cls[path] = callback.cls
return {path: (view_cls[path], methods) for path, methods in view_paths.items()}
[docs] def get_operation_keys(self, subpath, method, view):
"""Return a list of keys that should be used to group an operation within the specification.
::
/users/ ("users", "list"), ("users", "create")
/users/{pk}/ ("users", "read"), ("users", "update"), ("users", "delete")
/users/enabled/ ("users", "enabled") # custom viewset list action
/users/{pk}/star/ ("users", "star") # custom viewset detail action
/users/{pk}/groups/ ("users", "groups", "list"), ("users", "groups", "create")
/users/{pk}/groups/{pk}/ ("users", "groups", "read"), ("users", "groups", "update")
:param str subpath: path to the operation with any common prefix/base path removed
:param str method: HTTP method
:param view: the view associated with the operation
:rtype: tuple
"""
return self._gen.get_keys(subpath, method, view)
[docs] def get_paths(self, endpoints, components):
"""Generate the Swagger Paths for the API from the given endpoints.
:param dict endpoints: endpoints as returned by get_endpoints
:param ReferenceResolver components: resolver/container for Swagger References
:rtype: openapi.Paths
"""
if not endpoints:
return openapi.Paths(paths={})
prefix = self._gen.determine_path_prefix(endpoints.keys())
paths = OrderedDict()
default_schema_cls = SwaggerAutoSchema
for path, (view_cls, methods) in sorted(endpoints.items()):
path_parameters = self.get_path_parameters(path, view_cls)
operations = {}
for method, view in methods:
if not self._gen.has_view_permissions(path, method, view):
continue
operation_keys = self.get_operation_keys(path[len(prefix):], method, view)
overrides = self.get_overrides(view, method)
auto_schema_cls = overrides.get('auto_schema', default_schema_cls)
schema = auto_schema_cls(view, path, method, overrides, components)
operations[method.lower()] = schema.get_operation(operation_keys)
if operations:
paths[path] = openapi.PathItem(parameters=path_parameters, **operations)
return openapi.Paths(paths=paths)
[docs] def get_overrides(self, view, method):
"""Get overrides specified for a given operation.
:param view: the view associated with the operation
:param str method: HTTP method
:return: a dictionary containing any overrides set by :func:`@swagger_auto_schema <.swagger_auto_schema>`
:rtype: dict
"""
method = method.lower()
action = getattr(view, 'action', method)
action_method = getattr(view, action, None)
overrides = getattr(action_method, 'swagger_auto_schema', {})
if method in overrides:
overrides = overrides[method]
return overrides
[docs] def get_path_parameters(self, path, view_cls):
"""Return a list of Parameter instances corresponding to any templated path variables.
:param str path: templated request path
:param type view_cls: the view class associated with the path
:return: path parameters
:rtype: list[openapi.Parameter]
"""
parameters = []
model = getattr(getattr(view_cls, 'queryset', None), 'model', None)
for variable in uritemplate.variables(path):
pattern = None
type = openapi.TYPE_STRING
description = None
if model is not None:
# Attempt to infer a field description if possible.
try:
model_field = model._meta.get_field(variable)
except Exception: # pragma: no cover
model_field = None
if model_field is not None and model_field.help_text:
description = force_text(model_field.help_text)
elif model_field is not None and model_field.primary_key:
description = get_pk_description(model, model_field)
if hasattr(view_cls, 'lookup_value_regex') and getattr(view_cls, 'lookup_field', None) == variable:
pattern = view_cls.lookup_value_regex
elif isinstance(model_field, django.db.models.AutoField):
type = openapi.TYPE_INTEGER
field = openapi.Parameter(
name=variable,
required=True,
in_=openapi.IN_PATH,
type=type,
pattern=pattern,
description=description,
)
parameters.append(field)
return parameters