Class OutputModel not found in module jupyter-js-widgets

[ischurov]

I'm actually do not understand how brand new "rendering widgets in nbviewer" is expected to work, but I found, how it is not working.

I created a simple demo plotting a graph with matplotlib.pyplot and two sliders. It works in Jupyter but does not work in nbviewer.

The code is the following:

import ipywidgets as widgets
import matplotlib.pyplot as plt
%matplotlib inline
import numpy as np

@widgets.interact(a=widgets.FloatSlider(min=0, max=10, value=1, step=1e-3), 
          b=widgets.FloatSlider(min=0, max=10, value=1, step=1e-3))
def plot_sin(a, b):
    x = np.linspace(-4,4,300)
    plt.ylim(-2,2)
    plt.plot(np.sin(a*x)*b)
    plt.show()

Then I selected Widgets → Save Notebook with Widgets menu item, then uploaded ipynb-file to the server, then opened with nbviewer, see the link.

The actual sliders are rendered, but the output is not and I have the following error message instead of rendered content:

Could not create model:
Model name	OutputModel
Model module	jupyter-js-widgets
Model module version	~2.1.4
Class OutputModel not found in module jupyter-js-widgets

Actually, I didn't expect that my pictures will be shown correctly as they are dynamically created (depending on the positions of the sliders) on python side and nbviewer does not execute Python code. (The behaviour I theoretically might expect is that Jupyter tries to generate all possible combinations of pictures and instruct nbviewer to show the correct one depending on sliders, but it is obviously very time and space-consuming thing, especially if several widgets presented.) Anyway, currently the error message seem to be unclear for me. Is it a bug? A feature?

[janfreyberg]

+1, having the same issue with pyplot.imshow(). I get the exact same error message.

Mine is here:
http://nbviewer.jupyter.org/gist/janfreyberg/496e9d3f4a5ff2d41e7e0f3e60063ac4

[SylvainCorlay]

That is right. The output widget used by interact is the only widget not supported in web contexts other than notebook and lab.

Since multiple people are affected by this, I make this a priority for 6.0.1.

[janfreyberg]

Ah, that's great to know. Thanks!

[maartenbreddels]

Also hit by this here, good to see this is reported.

[jasongrout]

Closing as a duplicate of #986.