Add schema decorator for FBVs

Author: carltongibson

docs/api-guide/views.md

@@ -184,6 +184,28 @@ The available decorators are:
 
 Each of these decorators takes a single argument which must be a list or tuple of classes.
 
+
+## View schema decorator
+
+To override the default schema generation for function based views you may use
+the `@schema` decorator. This must come *after* (below) the `@api_view`
+decorator. For example:
+
+    from rest_framework.decorators import api_view, schema
+    from rest_framework.schemas import AutoSchema
+
+    class CustomAutoSchema(AutoSchema):
+        def get_link(*args):
+            # override view introspection here...
+
+    @api_view(['GET'])
+    @schema(CustomAutoSchema())
+    def view(request):
+        return Response({"message": "Hello for today! See you tomorrow!"})
+
+This decorator takes a single `AutoSchema` instance, an `AutoSchema` subclass
+instance or `ManualSchema` instance as described in the [Schemas documentation][schemas],
+
 [cite]: http://reinout.vanrees.org/weblog/2011/08/24/class-based-views-usage.html
 [cite2]: http://www.boredomandlaziness.org/2012/05/djangos-cbvs-are-not-mistake-but.html
 [settings]: settings.md

rest_framework/decorators.py

@@ -72,6 +72,9 @@ def handler(self, *args, **kwargs):
         WrappedAPIView.permission_classes = getattr(func, 'permission_classes',
                                                     APIView.permission_classes)
 
+        WrappedAPIView.schema = getattr(func, 'schema',
+                                        APIView.schema)
+
         WrappedAPIView.exclude_from_schema = exclude_from_schema
         return WrappedAPIView.as_view()
     return decorator
@@ -112,6 +115,13 @@ def decorator(func):
     return decorator
 
 
+def schema(view_inspector):
+    def decorator(func):
+        func.schema = view_inspector
+        return func
+    return decorator
+
+
 def detail_route(methods=None, **kwargs):
     """
     Used to mark a method on a ViewSet that should be routed for detail requests.

tests/test_decorators.py

@@ -6,12 +6,13 @@
 from rest_framework.authentication import BasicAuthentication
 from rest_framework.decorators import (
     api_view, authentication_classes, parser_classes, permission_classes,
-    renderer_classes, throttle_classes
+    renderer_classes, schema, throttle_classes
 )
 from rest_framework.parsers import JSONParser
 from rest_framework.permissions import IsAuthenticated
 from rest_framework.renderers import JSONRenderer
 from rest_framework.response import Response
+from rest_framework.schemas import AutoSchema
 from rest_framework.test import APIRequestFactory
 from rest_framework.throttling import UserRateThrottle
 from rest_framework.views import APIView
@@ -151,3 +152,17 @@ def view(request):
 
         response = view(request)
         assert response.status_code == status.HTTP_429_TOO_MANY_REQUESTS
+
+    def test_schema(self):
+        """
+        Checks CustomSchema class is set on view
+        """
+        class CustomSchema(AutoSchema):
+            pass
+
+        @api_view(['GET'])
+        @schema(CustomSchema())
+        def view(request):
+            return Response({})
+
+        assert isinstance(view.cls.schema, CustomSchema)