From d99550e54c3ebcafe5c9a67e1736d4062a13a867 Mon Sep 17 00:00:00 2001
From: Carlton Gibson <carlton.gibson@noumenal.es>
Date: Thu, 9 Aug 2018 09:19:23 +0200
Subject: [PATCH] Add Open API get_schema().

---
 rest_framework/schemas/generators.py | 26 +++++++++++++++++++++++---
 tests/schemas/test_openapi.py        | 19 +++++++++++++++----
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/rest_framework/schemas/generators.py b/rest_framework/schemas/generators.py
index 92cec8aa1..18693bed0 100644
--- a/rest_framework/schemas/generators.py
+++ b/rest_framework/schemas/generators.py
@@ -283,9 +283,7 @@ class SchemaGenerator(object):
         """
         Generate a `coreapi.Document` representing the API schema.
         """
-        if self.endpoints is None:
-            inspector = self.endpoint_inspector_cls(self.patterns, self.urlconf)
-            self.endpoints = inspector.get_api_endpoints()
+        self._initialise_endpoints()
 
         links = self.get_links(None if public else request)
         if not links:
@@ -301,6 +299,11 @@ class SchemaGenerator(object):
             url=url, content=links
         )
 
+    def _initialise_endpoints(self):
+        if self.endpoints is None:
+            inspector = self.endpoint_inspector_cls(self.patterns, self.urlconf)
+            self.endpoints = inspector.get_api_endpoints()
+
     def get_links(self, request=None):
         """
         Return a dictionary containing all the links that should be
@@ -491,3 +494,20 @@ class OpenAPISchemaGenerator(SchemaGenerator):
             result[subpath][method.lower()] = operation
 
         return result
+
+    def get_schema(self, request=None, public=False):
+        """
+        Generate a `coreapi.Document` representing the API schema.
+        """
+        self._initialise_endpoints()
+
+        paths = self.get_paths(None if public else request)
+        if not paths:
+            return None
+
+        schema = {
+            'basePath': self.url,
+            'paths': paths,
+        }
+
+        return schema
diff --git a/tests/schemas/test_openapi.py b/tests/schemas/test_openapi.py
index bdd5dc9ba..3b4882f31 100644
--- a/tests/schemas/test_openapi.py
+++ b/tests/schemas/test_openapi.py
@@ -47,14 +47,12 @@ class TestGenerator(TestCase):
         assert isinstance(views.ExampleListView.schema, OpenAPIAutoSchema)
 
     def test_paths_construction(self):
+        """Construction of the `paths` key."""
         patterns = [
             url(r'^example/?$', views.ExampleListView.as_view()),
         ]
         generator = OpenAPISchemaGenerator(patterns=patterns)
-
-        # This happens in get_schema()
-        inspector = generator.endpoint_inspector_cls(generator.patterns, generator.urlconf)
-        generator.endpoints = inspector.get_api_endpoints()
+        generator._initialise_endpoints()
 
         paths = generator.get_paths()
 
@@ -63,3 +61,16 @@ class TestGenerator(TestCase):
         assert len(example_operations) == 2
         assert 'get' in example_operations
         assert 'post' in example_operations
+
+    def test_schema_construction(self):
+        """Construction of the top level dictionary."""
+        patterns = [
+            url(r'^example/?$', views.ExampleListView.as_view()),
+        ]
+        generator = OpenAPISchemaGenerator(patterns=patterns)
+
+        request = create_request('/')
+        schema = generator.get_schema(request=request)
+
+        assert 'basePath' in schema
+        assert 'paths' in schema