Move comm package

python/ipywidgets/ipywidgets/__init__.py

@@ -21,28 +21,26 @@
 from ._version import __version__, __protocol_version__, __jupyter_widgets_controls_version__, __jupyter_widgets_base_version__
 
 import os
-from IPython import get_ipython
-from .widgets import *
+
 from traitlets import link, dlink
+from comm import get_comm_manager
+
+from .widgets import *
+
 
 def load_ipython_extension(ip):
     """Set up Jupyter to work with widgets"""
-    if not hasattr(ip, 'kernel'):
-        return
-    register_comm_target(ip.kernel)
+    register_comm_target()
 
-def register_comm_target(kernel=None):
+def register_comm_target():
     """Register the jupyter.widget comm target"""
-    if kernel is None:
-        kernel = get_ipython().kernel
-    kernel.comm_manager.register_target('jupyter.widget', Widget.handle_comm_opened)
-    kernel.comm_manager.register_target('jupyter.widget.control', Widget.handle_control_comm_opened)
+    comm_manager = get_comm_manager()
+
+    comm_manager.register_target('jupyter.widget', Widget.handle_comm_opened)
+    comm_manager.register_target('jupyter.widget.control', Widget.handle_control_comm_opened)
 
 def _handle_ipython():
     """Register with the comm target at import if running in Jupyter"""
-    ip = get_ipython()
-    if ip is None:
-        return
-    load_ipython_extension(ip)
+    register_comm_target()
 
 _handle_ipython()

python/ipywidgets/ipywidgets/widgets/tests/test_widget_templates.py

@@ -220,7 +220,6 @@ def test_update_dynamically(self, send_state): #pylint: disable=no-self-use
         assert box.layout.grid_template_areas == ('"top-left top-right"\n' +
                                                   '"top-left bottom-right"')
 
-        box.layout.comm.kernel = mock.MagicMock(spec=Kernel) #for mocking purposes
         send_state.reset_mock()
         box.bottom_left = button2
 
@@ -235,7 +234,6 @@ def test_update_dynamically(self, send_state): #pylint: disable=no-self-use
                                      bottom_left=None, bottom_right=button4)
         assert box.layout.grid_template_areas == ('"top-left top-right"\n' +
                                                   '"top-left bottom-right"')
-        box.layout.comm.kernel = mock.MagicMock(spec=Kernel) #for mocking purposes
         send_state.reset_mock()
         box.merge = False
         assert box.layout.grid_template_areas == ('"top-left top-right"\n' +

python/ipywidgets/ipywidgets/widgets/tests/test_widget_upload.py

@@ -76,7 +76,6 @@ def test_serialization_deserialization_integrity(self):
         from ipykernel.comm import Comm
         uploader = FileUpload()
         mock_comm = MagicMock(spec=Comm)
-        mock_comm.kernel = 'does not matter'
         mock_comm.send = MagicMock()
         uploader.comm = mock_comm
         message = {'value': [FILE_UPLOAD_FRONTEND_CONTENT]}

python/ipywidgets/ipywidgets/widgets/tests/utils.py

@@ -1,11 +1,10 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
 
-from ipykernel.comm import Comm
 from ipywidgets import Widget
 import ipywidgets.widgets.widget
 
-class DummyComm(Comm):
+class DummyComm():
     comm_id = 'a-b-c-d'
     kernel = 'Truthy'
 

python/ipywidgets/ipywidgets/widgets/widget.py

@@ -10,9 +10,9 @@
 from contextlib import contextmanager
 from collections.abc import Iterable
 from IPython import get_ipython
-from ipykernel.comm import Comm
+from comm import create_comm
 from traitlets import (
-    HasTraits, Unicode, Dict, Instance, List, Int, Set, Bytes, observe, default, Container,
+    Any, HasTraits, Unicode, Dict, Instance, List, Int, Set, Bytes, observe, default, Container,
     Undefined)
 from json import loads as jsonloads, dumps as jsondumps
 
@@ -480,7 +480,7 @@ def get_view_spec(self):
 
     _view_count = Int(None, allow_none=True,
         help="EXPERIMENTAL: The number of views of the model displayed in the frontend. This attribute is experimental and may change or be removed in the future. None signifies that views will not be tracked. Set this to 0 to start tracking view creation/deletion.").tag(sync=True)
-    comm = Instance('ipykernel.comm.Comm', allow_none=True)
+    comm = Any(None, allow_none=True)
 
     keys = List(help="The traits which are synced.")
 
@@ -525,7 +525,7 @@ def open(self):
             if self._model_id is not None:
                 args['comm_id'] = self._model_id
 
-            self.comm = Comm(**args)
+            self.comm = create_comm(**args)
 
     @observe('comm')
     def _comm_changed(self, change):
@@ -686,11 +686,10 @@ def notify_change(self, change):
         # Send the state to the frontend before the user-registered callbacks
         # are called.
         name = change['name']
-        if self.comm is not None and self.comm.kernel is not None:
-            # Make sure this isn't information that the front-end just sent us.
-            if name in self.keys and self._should_send_property(name, getattr(self, name)):
-                # Send new state to front-end
-                self.send_state(key=name)
+        # Make sure this isn't information that the front-end just sent us.
+        if name in self.keys and self._should_send_property(name, getattr(self, name)):
+            # Send new state to front-end
+            self.send_state(key=name)
         super().notify_change(change)
 
     def __repr__(self):
@@ -814,7 +813,7 @@ def _repr_mimebundle_(self, **kwargs):
 
     def _send(self, msg, buffers=None):
         """Sends a message to the model in the front-end."""
-        if self.comm is not None and self.comm.kernel is not None:
+        if self.comm is not None:
             self.comm.send(data=msg, buffers=buffers)
 
     def _repr_keys(self):

python/ipywidgets/ipywidgets/widgets/widget_output.py

@@ -111,9 +111,7 @@ def __enter__(self):
         kernel = None
         if ip and getattr(ip, "kernel", None) is not None:
             kernel = ip.kernel
-        elif self.comm is not None and self.comm.kernel is not None:
-            kernel = self.comm.kernel
-
+
         if kernel:
             parent = None
             if hasattr(kernel, "get_parent"):
@@ -134,15 +132,6 @@ def __exit__(self, etype, evalue, tb):
             if ip:
                 kernel = ip
                 ip.showtraceback((etype, evalue, tb), tb_offset=0)
-            elif self.comm is not None and self.comm.kernel is not None:
-                kernel = self.comm.kernel
-                kernel.send_response(kernel.iopub_socket,
-                                     u'error',
-                                     {
-                    u'traceback': ["".join(traceback.format_exception(etype, evalue, tb))],
-                    u'evalue': repr(evalue.args),
-                    u'ename': etype.__name__
-                    })
         self._flush()
         self.__counter -= 1
         if self.__counter == 0: