Obtain preferred response format from Accept header

test/test_app_actions.py

@@ -677,6 +677,31 @@ def test_permission_check2(self, mock_abort):
             except FileNotFoundError:
                 pass
 
+    def test_accept_format(self):
+        """Test that `Accept` HTTP header causes change of response format
+
+        - Default `text/html` is tested by `TestView.test_directory`.
+        - `f=json` parameter is tested by `test_directory` in this class.
+        """
+        with app.test_client() as c:
+
+            r = c.get(
+                '/subdir/',
+                query_string={'a': 'info'},
+                headers=[('Accept', 'application/json')])
+            self.assertEqual(r.status_code, 200)
+            self.assertEqual(r.headers['Content-Type'], 'application/json')
+            self.assertEqual(r.json, {
+                'success': True,
+                'data': {
+                    'name': 'subdir',
+                    'type': 'dir',
+                    'size': None,
+                    'last_modified': os.stat(os.path.join(server_root, 'subdir')).st_mtime,
+                    'mime': None,
+                    },
+                })
+
     def test_directory(self):
         with app.test_client() as c:
             r = c.get('/subdir', query_string={'a': 'info', 'f': 'json'})
@@ -1263,6 +1288,18 @@ def test_sse_directory(self):
                     os.stat(os.path.join(server_root, 'subdir', 'sub')).st_mtime) in data)
             self.assertTrue(data.endswith('\n\nevent: complete\ndata: \n\n'))
 
+            headers=[('Accept', 'text/event-stream')]
+            with self.subTest(headers=headers):
+                r = c.get('/subdir/', query_string={'a': 'list'}, headers=headers)
+                self.assertEqual(r.status_code, 200)
+                self.assertEqual(r.headers['Content-Type'], 'text/event-stream; charset=utf-8')
+                data = r.data.decode('UTF-8')
+                self.assertTrue('data: {{"name": "file.txt", "type": "file", "size": 3, "last_modified": {}}}\n\n'.format(
+                        os.stat(os.path.join(server_root, 'subdir', 'file.txt')).st_mtime) in data)
+                self.assertTrue('data: {{"name": "sub", "type": "dir", "size": null, "last_modified": {}}}\n\n'.format(
+                        os.stat(os.path.join(server_root, 'subdir', 'sub')).st_mtime) in data)
+                self.assertTrue(data.endswith('\n\nevent: complete\ndata: \n\n'))
+
     def test_sse_directory_recursive(self):
         with app.test_client() as c:
             r = c.get('/subdir', query_string={'a': 'list', 'f': 'sse', 'recursive': 1})

webscrapbook/app.py

@@ -585,7 +585,13 @@ def action(self):
     @cached_property
     def format(self):
         """Shortcut of the requested format."""
-        rv = request.values.get('f')
+        rv = None
+        best_accept = request.accept_mimetypes.best
+        if best_accept == 'application/json':
+            rv = 'json'
+        elif best_accept == 'text/event-stream':
+            rv = 'sse'
+        rv = request.values.get('f', default=rv)
         rv = request.values.get('format', default=rv)
         return rv