From a58879f3d4db7e4e1e9b9a0cede2371b3cb1979f Mon Sep 17 00:00:00 2001
From: Miguel Grinberg <miguelgrinberg50@gmail.com>
Date: Sat, 26 Apr 2014 18:43:53 -0700
Subject: [PATCH] show a more friendly error when a server that is not
 compatible with gevent-socketio is used

---
 flask_socketio/__init__.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/flask_socketio/__init__.py b/flask_socketio/__init__.py
index 932428ac..0977c828 100644
--- a/flask_socketio/__init__.py
+++ b/flask_socketio/__init__.py
@@ -21,6 +21,8 @@ def __init__(self, app, socket):
     def __call__(self, environ, start_response):
         path = environ['PATH_INFO'].strip('/')
         if path is not None and path.startswith('socket.io'):
+            if 'socketio' not in environ:
+                raise RuntimeError('You need to use a gevent-socketio server.')
             socketio_manage(environ, self.socket.get_namespaces(), self.app,
                             json_loads=json.loads, json_dumps=json.dumps)
         else: