Source code for

import logging
import os

from functools import partial

import ipykernel
import jupyter_client.session as session
import param

from import MessageSentEvent
from bokeh.document.json import Literal, MessageSent, TypedDict
from bokeh.util.serialization import make_id
from ipykernel.comm import Comm, CommManager
from ipykernel.kernelbase import Kernel
from ipywidgets import Widget
from ipywidgets._version import __protocol_version__
from ipywidgets.widgets.widget import _remove_buffers

# Stop ipywidgets_bokeh from patching the kernel
ipykernel.kernelbase.Kernel._instance = ''

from ipywidgets_bokeh.kernel import (
    BokehKernel, SessionWebsocket, WebsocketStream,
from ipywidgets_bokeh.widget import IPyWidget
from tornado.ioloop import IOLoop
from traitlets import Any

from ..config import __version__
from ..util import classproperty
from .state import set_curdoc, state

    # Support for ipywidgets>=8.0.5
    import comm

    from comm.base_comm import BaseComm

[docs] class TempComm(BaseComm): def publish_msg(self, *args, **kwargs): pass
comm.create_comm = lambda *args, **kwargs: TempComm(target_name='panel-temp-comm', primary=False) except Exception: comm = None def _get_kernel(cls=None, doc=None): doc = doc or state.curdoc if doc is None: return _ORIG_KERNEL elif doc in state._ipykernels: return state._ipykernels[doc] state._ipykernels[doc] = kernel = PanelKernel(document=doc, key=str(id(doc)).encode('utf-8')) return kernel def _get_ipywidgets(): # Support ipywidgets >=8.0 and <8.0 try: from ipywidgets.widgets.widget import _instances as widgets except Exception: widgets = Widget.widgets return widgets def _on_widget_constructed(widget, doc=None): doc = doc or state.curdoc if not doc or getattr(widget, '_document', None) not in (doc, None): return widget._document = doc kernel = _get_kernel(doc=doc) if (widget.comm and widget.comm.target_name != 'panel-temp-comm' and (not (comm and isinstance(widget.comm, comm.DummyComm)) and isinstance(widget.comm.kernel, PanelKernel))): return wstate, buffer_paths, buffers = _remove_buffers(widget.get_state()) args = { 'target_name': 'jupyter.widget', 'data': { 'state': wstate, 'buffer_paths': buffer_paths }, 'buffers': buffers, 'metadata': { 'version': __protocol_version__ } } if widget._model_id is not None: args['comm_id'] = widget._model_id try: widget.comm = Comm(**args) except Exception as e: if 'PANEL_IPYWIDGET' not in os.environ: raise e kernel.register_widget(widget) # Patch font-awesome CSS onto ipywidgets_bokeh IPyWidget IPyWidget.__css__ = [ "" ]
[docs]class MessageSentBuffers(TypedDict): kind: Literal["MessageSent"] msg_type: str
[docs]class MessageSentEventPatched(MessageSentEvent): """ Patches MessageSentEvent with fix that ensures MessageSent event does not define msg_data (which is an assumption in BokehJS Document.apply_json_patch.) """ def generate(self, references, buffers): if not isinstance(self.msg_data, bytes): msg = MessageSent( kind=self.kind, msg_type=self.msg_type, msg_data=self.msg_data ) else: msg = MessageSentBuffers( kind=self.kind, msg_type=self.msg_type ) assert buffers is not None buffer_id = make_id() buf = (dict(id=buffer_id), self.msg_data) buffers.append(buf) return msg
[docs]class PanelSessionWebsocket(SessionWebsocket): def __init__(self, *args, **kwargs): session.Session.__init__(self, *args, **kwargs) self._document = kwargs.pop('document', None) self._queue = [] self._document.on_message("ipywidgets_bokeh", self.receive)
[docs] def send(self, stream, msg_type, content=None, parent=None, ident=None, buffers=None, track=False, header=None, metadata=None): msg = self.msg(msg_type, content=content, parent=parent, header=header, metadata=metadata) try: msg['channel'] = except Exception: return packed = self.pack(msg) if buffers is not None and len(buffers) != 0: buffers = [packed] + buffers nbufs = len(buffers) start = 4*(1 + nbufs) offsets = [start] for buffer in buffers[:-1]: start += memoryview(buffer).nbytes offsets.append(start) u32 = lambda n: n.to_bytes(4, "big") items = [u32(nbufs)] + [ u32(offset) for offset in offsets ] + buffers data = b"".join(items) else: data = packed.decode("utf-8") event = MessageSentEventPatched(self._document, "ipywidgets_bokeh", data) self._queue.append(event) self._document.add_next_tick_callback(self._dispatch)
def _dispatch(self): try: for event in self._queue: self._document.callbacks.trigger_on_change(event) except Exception as e: param.main.param.warning(f'ipywidgets event dispatch failed with: {e}') finally: self._queue = []
class ShellStream: def flush(self, *args): pass
[docs]class PanelKernel(Kernel): implementation = 'panel' implementation_version = __version__ banner = 'banner' shell_stream = Any(ShellStream(), allow_none=True) def __init__(self, key=None, document=None): super().__init__() self.session = PanelSessionWebsocket(document=document, parent=self, key=key) = self.iopub_socket = WebsocketStream(self.session) self.io_loop = IOLoop.current() = 'iopub' = self.iopub_socket self.comm_manager = CommManager(parent=self, kernel=self) = None self.session.auth = None self.log = logging.getLogger('fake') comm_msg_types = ['comm_open', 'comm_msg', 'comm_close'] for msg_type in comm_msg_types: handler = getattr(self.comm_manager, msg_type) self.shell_handlers[msg_type] = self._wrap_handler(msg_type, handler) async def _flush_control_queue(self): pass def register_widget(self, widget): comm = widget.comm comm.kernel = self self.comm_manager.register_comm(comm) def _wrap_handler(self, msg_type, handler): doc = self.session._document def wrapper(*args, **kwargs): if msg_type == 'comm_open': return with set_curdoc(doc): state.execute(partial(handler, *args, **kwargs), schedule=True) return wrapper
# Patch kernel and widget objects _ORIG_KERNEL = ipykernel.kernelbase.Kernel._instance if isinstance(ipykernel.kernelbase.Kernel._instance, (BokehKernel, str)): ipykernel.kernelbase.Kernel._instance = classproperty(_get_kernel) Widget.on_widget_constructed(_on_widget_constructed)