Merge pull request #84 from plotly/async-kernel

support async kernel in _request_jupyter_config

Author: alexcjohnson

jupyter_dash/comms.py

@@ -1,5 +1,7 @@
+import asyncio
 import IPython
 from ipykernel.comm import Comm
+import nest_asyncio
 import time
 import sys
 
@@ -66,7 +68,12 @@ def capture_event(stream, ident, parent):
         if _jupyter_comm_response_received():
             break
 
-        kernel.do_one_iteration()
+        if asyncio.iscoroutinefunction(kernel.do_one_iteration):
+            nest_asyncio.apply()
+            loop = asyncio.get_event_loop()
+            loop.run_until_complete(kernel.do_one_iteration())
+        else:
+            kernel.do_one_iteration()
 
     # Stop capturing events, revert the kernel shell handler to the default
     # execute_request behavior

jupyter_dash/jupyter_app.py

@@ -220,6 +220,8 @@ def run_server(
         old_server = self._server_threads.get((host, port))
         if old_server:
             old_server.kill()
+            old_server.join()
+            del self._server_threads[(host, port)]
 
         # Configure pathname prefix
         requests_pathname_prefix = self.config.get('requests_pathname_prefix', None)

requirements.txt

@@ -5,3 +5,4 @@ retrying
 ipython
 ipykernel
 ansi2html
+nest-asyncio