From f4d62c54678f6866072359333ad2beb737a36992 Mon Sep 17 00:00:00 2001
From: Carlton Gibson <carlton.gibson@noumenal.es>
Date: Tue, 5 Dec 2017 11:54:56 +0100
Subject: [PATCH] Add DefaultSchema utility

---
 rest_framework/schemas/__init__.py   |  2 +-
 rest_framework/schemas/inspectors.py | 11 +++++++++++
 rest_framework/settings.py           |  4 ++++
 rest_framework/views.py              |  4 ++--
 tests/test_schemas.py                |  2 +-
 5 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/rest_framework/schemas/__init__.py b/rest_framework/schemas/__init__.py
index 1af0b9fc5..ba0ec6536 100644
--- a/rest_framework/schemas/__init__.py
+++ b/rest_framework/schemas/__init__.py
@@ -23,7 +23,7 @@ Other access should target the submodules directly
 from rest_framework.settings import api_settings
 
 from .generators import SchemaGenerator
-from .inspectors import AutoSchema, ManualSchema  # noqa
+from .inspectors import AutoSchema, DefaultSchema, ManualSchema  # noqa
 
 
 def get_schema_view(
diff --git a/rest_framework/schemas/inspectors.py b/rest_framework/schemas/inspectors.py
index 008d7c091..8a811473c 100644
--- a/rest_framework/schemas/inspectors.py
+++ b/rest_framework/schemas/inspectors.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 """
 inspectors.py   # Per-endpoint view introspection
 
@@ -456,3 +457,13 @@ class ManualSchema(ViewInspector):
         )
 
         return self._link
+
+
+class DefaultSchema(object):
+    """Allows overriding AutoSchema in with DEFAULT_SCHEMA_CLASS setting"""
+    def __get__(self, instance, owner):
+        inspector_class = api_settings.DEFAULT_SCHEMA_CLASS
+        assert issubclass(inspector_class, ViewInspector), "DEFAULT_SCHEMA_CLASS must be set to a ViewInspector (usually an AutoSchema) subclass"
+        inspector = inspector_class()
+        inspector.view = instance
+        return inspector
diff --git a/rest_framework/settings.py b/rest_framework/settings.py
index 478a5229f..db92b7a7b 100644
--- a/rest_framework/settings.py
+++ b/rest_framework/settings.py
@@ -55,6 +55,9 @@ DEFAULTS = {
     'DEFAULT_PAGINATION_CLASS': None,
     'DEFAULT_FILTER_BACKENDS': (),
 
+    # Schema
+    'DEFAULT_SCHEMA_CLASS': 'rest_framework.schemas.AutoSchema',
+
     # Throttling
     'DEFAULT_THROTTLE_RATES': {
         'user': None,
@@ -140,6 +143,7 @@ IMPORT_STRINGS = (
     'DEFAULT_VERSIONING_CLASS',
     'DEFAULT_PAGINATION_CLASS',
     'DEFAULT_FILTER_BACKENDS',
+    'DEFAULT_SCHEMA_CLASS',
     'EXCEPTION_HANDLER',
     'TEST_REQUEST_RENDERER_CLASSES',
     'UNAUTHENTICATED_USER',
diff --git a/rest_framework/views.py b/rest_framework/views.py
index 3140bb9a3..f9ee7fb53 100644
--- a/rest_framework/views.py
+++ b/rest_framework/views.py
@@ -18,7 +18,7 @@ from django.views.generic import View
 from rest_framework import exceptions, status
 from rest_framework.request import Request
 from rest_framework.response import Response
-from rest_framework.schemas import AutoSchema
+from rest_framework.schemas import DefaultSchema
 from rest_framework.settings import api_settings
 from rest_framework.utils import formatting
 
@@ -117,7 +117,7 @@ class APIView(View):
     # Allow dependency injection of other settings to make testing easier.
     settings = api_settings
 
-    schema = AutoSchema()
+    schema = DefaultSchema()
 
     @classmethod
     def as_view(cls, **initkwargs):
diff --git a/tests/test_schemas.py b/tests/test_schemas.py
index 6de875521..fa91bac03 100644
--- a/tests/test_schemas.py
+++ b/tests/test_schemas.py
@@ -536,7 +536,7 @@ class TestAutoSchema(TestCase):
         assert isinstance(view.schema, CustomViewInspector)
 
     def test_set_custom_inspector_class_via_settings(self):
-        with override_settings(REST_FRAMEWORK={'DEFAULT_SCHEMA_CLASS':'tests.test_schemas.CustomViewInspector'}):
+        with override_settings(REST_FRAMEWORK={'DEFAULT_SCHEMA_CLASS': 'tests.test_schemas.CustomViewInspector'}):
             view = APIView()
             assert isinstance(view.schema, CustomViewInspector)