Compatibility with Jupyter Notebook is broken

[lrq3000]

Here is my code:

from flexx import flx
flx.init_notebook()
%gui asyncio

Here is the output:

[I 18:20:42 flexx.app] Asset store collected 2 new modules.
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-1-c5872d64e577> in <module>
      1 from flexx import flx
----> 2 flx.init_notebook()
      3 get_ipython().run_line_magic('gui', 'asyncio')

~\Anaconda3\lib\site-packages\flexx\app\_funcs.py in init_notebook()
    169 
    170     # Install helper to make things work in exported notebooks
--> 171     NoteBookHelper(session)
    172 
    173     proto = 'wss' if server.protocol == 'https' else 'ws'

~\Anaconda3\lib\site-packages\flexx\app\_funcs.py in __init__(self, session)
     85         self._real_ws = None
     86         self._commands = []
---> 87         self.enable()
     88 
     89     def enable(self):

~\Anaconda3\lib\site-packages\flexx\app\_funcs.py in enable(self)
     90         get_ipython = None
     91         exec("from IPython import get_ipython")  # noqa - dont trigger e.g. PyInstaller
---> 92         ip = get_ipython()
     93         ip.events.register('pre_execute', self.capture)
     94         ip.events.register('post_execute', self.release)

TypeError: 'NoneType' object is not callable

I think the API changed

[almarklein]

Thanks for reporting this. If anyone knows what change is needed, a PR is welcome.