From 1084dca22b0b23e87ff37708f8071cfbf4f23bb4 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Wed, 5 Oct 2016 16:14:23 +0100
Subject: [PATCH] Better descriptions for schemas

---
 docs/api-guide/schemas.md | 55 +++++++++++++++++++++++++++++++++++++++
 rest_framework/schemas.py | 21 ++++++++-------
 tests/test_schemas.py     |  4 +++
 3 files changed, 71 insertions(+), 9 deletions(-)

diff --git a/docs/api-guide/schemas.md b/docs/api-guide/schemas.md
index 868207dac..16d2bbb01 100644
--- a/docs/api-guide/schemas.md
+++ b/docs/api-guide/schemas.md
@@ -247,6 +247,61 @@ You could then either:
 One common usage of API schemas is to use them to build documentation pages.
 
 The schema generation in REST framework uses docstrings to automatically
+populate descriptions in the schema document.
+
+These descriptions will be based on:
+
+* The corresponding method docstring if one exists.
+* A named section within the class docstring, which can be either single line or multi-line.
+* The class docstring.
+
+## Examples
+
+An `APIView`, with an explicit method docstring.
+
+    class ListUsernames(APIView):
+        def get(self, request):
+            """
+            Return a list of all user names in the system.
+            """
+            usernames = [user.username for user in User.objects.all()]
+            return Response(usernames)
+
+A `ViewSet`, with an explict action docstring.
+
+    class ListUsernames(ViewSet):
+        def list(self, request):
+            """
+            Return a list of all user names in the system.
+            """
+            usernames = [user.username for user in User.objects.all()]
+            return Response(usernames)
+
+A generic view with sections in the class docstring, using single-line style.
+
+    class UserList(generics.ListCreateAPIView):
+        """
+        get: Create a new user.
+        post: List all the users.
+        """
+        queryset = User.objects.all()
+        serializer_class = UserSerializer
+        permission_classes = (IsAdminUser,)
+
+A generic viewset with sections in the class docstring, using multi-line style.
+
+    class UserViewSet(viewsets.ModelViewSet):
+        """
+        API endpoint that allows users to be viewed or edited.
+
+        retrieve:
+        Return a user instance.
+
+        list:
+        Return all users, ordered by most recently joined.
+        """
+        queryset = User.objects.all().order_by('-date_joined')
+        serializer_class = UserSerializer
 
 ---
 
diff --git a/rest_framework/schemas.py b/rest_framework/schemas.py
index dc4d8acb7..ad311dcfd 100644
--- a/rest_framework/schemas.py
+++ b/rest_framework/schemas.py
@@ -5,7 +5,7 @@ from importlib import import_module
 from django.conf import settings
 from django.contrib.admindocs.views import simplify_regex
 from django.utils import six
-from django.utils.encoding import force_text
+from django.utils.encoding import force_text, smart_text
 
 from rest_framework import exceptions, renderers, serializers
 from rest_framework.compat import (
@@ -14,6 +14,7 @@ from rest_framework.compat import (
 from rest_framework.request import clone_request
 from rest_framework.response import Response
 from rest_framework.settings import api_settings
+from rest_framework.utils import formatting
 from rest_framework.views import APIView
 
 header_regex = re.compile('^[a-zA-Z][0-9A-Za-z_]*:')
@@ -297,15 +298,17 @@ class SchemaGenerator(object):
         """
         Determine a link description.
 
-        This with either be the class docstring, or a specific section for it.
-
-        For views, use method names, eg `get:` to introduce a section.
-        For viewsets, use action names, eg `retrieve:` to introduce a section.
-
-        The section names will correspond to the methods on the class.
+        This will be based on the method docstring if one exists,
+        or else the class docstring.
         """
-        view_description = view.get_view_description()
-        lines = [line.strip() for line in view_description.splitlines()]
+        method_name = getattr(view, 'action', method.lower())
+        method_docstring = getattr(view, method_name, None).__doc__
+        if method_docstring:
+            # An explicit docstring on the method or action.
+            return formatting.dedent(smart_text(method_docstring))
+
+        description = view.get_view_description()
+        lines = [line.strip() for line in description.splitlines()]
         current_section = ''
         sections = {'': ''}
 
diff --git a/tests/test_schemas.py b/tests/test_schemas.py
index 1fc7c218e..edc602d98 100644
--- a/tests/test_schemas.py
+++ b/tests/test_schemas.py
@@ -46,6 +46,9 @@ class ExampleViewSet(ModelViewSet):
 
     @detail_route(methods=['post'], serializer_class=AnotherSerializer)
     def custom_action(self, request, pk):
+        """
+        A description of custom action.
+        """
         return super(ExampleSerializer, self).retrieve(self, request)
 
     @list_route()
@@ -149,6 +152,7 @@ class TestRouterGeneratedSchema(TestCase):
                         url='/example/{pk}/custom_action/',
                         action='post',
                         encoding='application/json',
+                        description='A description of custom action.',
                         fields=[
                             coreapi.Field('pk', required=True, location='path'),
                             coreapi.Field('c', required=True, location='form'),