Make comm_manager a property of kernel, not shell

IPython/core/interactiveshell.py

@@ -523,7 +523,6 b' class InteractiveShell(SingletonConfigurable):'
         self.init_pdb()
         self.init_extension_manager()
         self.init_payload()
-        self.init_comms()
         self.hooks.late_startup_hook()
         self.events.trigger('shell_initialized', self)
         atexit.register(self.atexit_operations)
@@ -2419,14 +2418,6 b' class InteractiveShell(SingletonConfigurable):'
         self.configurables.append(self.payload_manager)
     
     #-------------------------------------------------------------------------
-    # Things related to widgets
-    #-------------------------------------------------------------------------
-    
-    def init_comms(self):
-        # not implemented in the base class
-        pass
-    
-    #-------------------------------------------------------------------------
     # Things related to the prefilter
     #-------------------------------------------------------------------------
 

IPython/html/widgets/tests/test_interaction.py

@@ -22,6 +22,9 b' from IPython.utils.py3compat import annotate'
 class DummyComm(Comm):
     comm_id = 'a-b-c-d'
     
+    def open(self, *args, **kwargs):
+        pass
+    
     def send(self, *args, **kwargs):
         pass
     

IPython/kernel/comm/comm.py

@@ -6,7 +6,7 b''
 import uuid
 
 from IPython.config import LoggingConfigurable
-from IPython.core.getipython import get_ipython
+from IPython.kernel.zmq.kernelbase import Kernel
 
 from IPython.utils.jsonutil import json_clean
 from IPython.utils.traitlets import Instance, Unicode, Bytes, Bool, Dict, Any
@@ -18,6 +18,9 b' class Comm(LoggingConfigurable):'
     shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
                      allow_none=True)
     kernel = Instance('IPython.kernel.zmq.kernelbase.Kernel')
+    def _kernel_default(self):
+        if Kernel.initialized():
+            return Kernel.instance()
     
     iopub_socket = Any()
     def _iopub_socket_default(self):
@@ -55,16 +58,15 b' class Comm(LoggingConfigurable):'
     
     def _publish_msg(self, msg_type, data=None, metadata=None, **keys):
         """Helper for sending a comm message on IOPub"""
-        if self.session is not None:
-            data = {} if data is None else data
-            metadata = {} if metadata is None else metadata
-            content = json_clean(dict(data=data, comm_id=self.comm_id, **keys))
-            self.session.send(self.iopub_socket, msg_type,
-                content,
-                metadata=json_clean(metadata),
-                parent=self.kernel._parent_header,
-                ident=self.topic,
-            )
+        data = {} if data is None else data
+        metadata = {} if metadata is None else metadata
+        content = json_clean(dict(data=data, comm_id=self.comm_id, **keys))
+        self.session.send(self.iopub_socket, msg_type,
+            content,
+            metadata=json_clean(metadata),
+            parent=self.kernel._parent_header,
+            ident=self.topic,
+        )
     
     def __del__(self):
         """trigger close on gc"""
@@ -76,10 +78,13 b' class Comm(LoggingConfigurable):'
         """Open the frontend-side version of this comm"""
         if data is None:
             data = self._open_data
+        comm_manager = getattr(self.kernel, 'comm_manager', None)
+        if comm_manager is None:
+            raise RuntimeError("Comms cannot be opened without a kernel "
+                        "and a comm_manager attached to that kernel.")
+
+        comm_manager.register_comm(self)
         self._closed = False
-        ip = get_ipython()
-        if hasattr(ip, 'comm_manager'):
-            ip.comm_manager.register_comm(self)
         self._publish_msg('comm_open', data, metadata, target_name=self.target_name)
     
     def close(self, data=None, metadata=None):
@@ -90,9 +95,7 b' class Comm(LoggingConfigurable):'
         if data is None:
             data = self._close_data
         self._publish_msg('comm_close', data, metadata)
-        ip = get_ipython()
-        if hasattr(ip, 'comm_manager'):
-            ip.comm_manager.unregister_comm(self)
+        self.kernel.comm_manager.unregister_comm(self)
         self._closed = True
     
     def send(self, data=None, metadata=None):

IPython/kernel/zmq/ipkernel.py

@@ -10,6 +10,7 b' from IPython.utils.tokenutil import token_at_cursor'
 from IPython.utils.traitlets import Instance, Type, Any
 from IPython.utils.decorators import undoc
 
+from ..comm import CommManager
 from .kernelbase import Kernel as KernelBase
 from .serialize import serialize_object, unpack_apply_message
 from .zmqshell import ZMQInteractiveShell
@@ -55,10 +56,12 b' class IPythonKernel(KernelBase):'
         # TMP - hack while developing
         self.shell._reply_content = None
 
+        self.comm_manager = CommManager(shell=self.shell, parent=self, 
+                                        kernel=self)
+        self.shell.configurables.append(self.comm_manager)
         comm_msg_types = [ 'comm_open', 'comm_msg', 'comm_close' ]
-        comm_manager = self.shell.comm_manager
         for msg_type in comm_msg_types:
-            self.shell_handlers[msg_type] = getattr(comm_manager, msg_type)
+            self.shell_handlers[msg_type] = getattr(self.comm_manager, msg_type)
 
     # Kernel info fields
     implementation = 'ipython'

IPython/kernel/zmq/kernelapp.py

@@ -306,7 +306,7 b' class IPKernelApp(BaseIPythonApplication, InteractiveShellApp,'
         shell_stream = ZMQStream(self.shell_socket)
         control_stream = ZMQStream(self.control_socket)
         
-        kernel_factory = self.kernel_class
+        kernel_factory = self.kernel_class.instance
 
         kernel = kernel_factory(parent=self, session=self.session,
                                 shell_streams=[shell_stream, control_stream],

IPython/kernel/zmq/kernelbase.py

@@ -19,7 +19,7 b' import zmq'
 from zmq.eventloop import ioloop
 from zmq.eventloop.zmqstream import ZMQStream
 
-from IPython.config.configurable import Configurable
+from IPython.config.configurable import SingletonConfigurable
 from IPython.core.error import StdinNotImplementedError
 from IPython.core import release
 from IPython.utils import py3compat
@@ -32,7 +32,7 b' from IPython.utils.traitlets import ('
 from .session import Session
 
 
-class Kernel(Configurable):
+class Kernel(SingletonConfigurable):
 
     #---------------------------------------------------------------------------
     # Kernel interface

IPython/kernel/zmq/zmqshell.py

@@ -49,7 +49,6 b' from IPython.utils.warn import error'
 from IPython.kernel.zmq.displayhook import ZMQShellDisplayHook
 from IPython.kernel.zmq.datapub import ZMQDataPublisher
 from IPython.kernel.zmq.session import extract_header
-from IPython.kernel.comm import CommManager
 from .session import Session
 
 #-----------------------------------------------------------------------------
@@ -563,11 +562,6 b' class ZMQInteractiveShell(InteractiveShell):'
         super(ZMQInteractiveShell, self).init_magics()
         self.register_magics(KernelMagics)
         self.magics_manager.register_alias('ed', 'edit')
-    
-    def init_comms(self):
-        self.comm_manager = CommManager(shell=self, parent=self, 
-                                        kernel=self.kernel)
-        self.configurables.append(self.comm_manager)
 
 
 InteractiveShellABC.register(ZMQInteractiveShell)