Add ViewInspector setter to store instances

rest_framework/schemas/generators.py

@@ -365,9 +365,7 @@ class SchemaGenerator(object):
         """
         Given a callback, return an actual view instance.
         """
-        view = callback.cls()
-        for attr, val in getattr(callback, 'initkwargs', {}).items():
-            setattr(view, attr, val)
+        view = callback.cls(**getattr(callback, 'initkwargs', {}))
         view.args = ()
         view.kwargs = {}
         view.format_kwarg = None

rest_framework/schemas/inspectors.py

@@ -7,6 +7,7 @@ See schemas.__init__.py for package overview.
 import re
 import warnings
 from collections import OrderedDict
+from weakref import WeakKeyDictionary
 
 from django.db import models
 from django.utils.encoding import force_text, smart_text
@@ -128,6 +129,10 @@ class ViewInspector(object):
 
     Provide subclass for per-view schema generation
     """
+
+    def __init__(self):
+        self.instance_schemas = WeakKeyDictionary()
+
     def __get__(self, instance, owner):
         """
         Enables `ViewInspector` as a Python _Descriptor_.
@@ -144,9 +149,16 @@ class ViewInspector(object):
         See: https://docs.python.org/3/howto/descriptor.html for info on
         descriptor usage.
         """
+        if instance in self.instance_schemas:
+            return self.instance_schemas[instance]
+
         self.view = instance
         return self
 
+    def __set__(self, instance, other):
+        self.instance_schemas[instance] = other
+        other.view = instance
+
     @property
     def view(self):
         """View property."""
@@ -189,6 +201,7 @@ class AutoSchema(ViewInspector):
         * `manual_fields`: list of `coreapi.Field` instances that
             will be added to auto-generated fields, overwriting on `Field.name`
         """
+        super(AutoSchema, self).__init__()
         if manual_fields is None:
             manual_fields = []
         self._manual_fields = manual_fields
@@ -455,6 +468,7 @@ class ManualSchema(ViewInspector):
         * `fields`: list of `coreapi.Field` instances.
         * `descripton`: String description for view. Optional.
         """
+        super(ManualSchema, self).__init__()
         assert all(isinstance(f, coreapi.Field) for f in fields), "`fields` must be a list of coreapi.Field instances"
         self._fields = fields
         self._description = description
@@ -474,9 +488,13 @@ class ManualSchema(ViewInspector):
         )
 
 
-class DefaultSchema(object):
+class DefaultSchema(ViewInspector):
     """Allows overriding AutoSchema using DEFAULT_SCHEMA_CLASS setting"""
     def __get__(self, instance, owner):
+        result = super(DefaultSchema, self).__get__(instance, owner)
+        if not isinstance(result, DefaultSchema):
+            return result
+
         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()