🤖 hack together output retention in notebooks

[jvdd]

This PR does;

• retain some output of FigureResampler when notebook is disconnected
• test the above (just 1 minimal test that runs the code)
• monitor browser logs in selenium tests (Improve selenium tests #16)

Look more into;

• rethink the _ipython_display_ for FigureResampler? @jonasvdd
• Incorporating this into the example notebooks

How does this work;

This PR adds additional JavaScript code to the IPython.display.display method, which contains a base64 bytarray image of the shown figure. When the dash app is not reachable, the image is shown instead of the iframe (which embedded the connected dash app). This works because the JavaScript in the notebook output cells gets executed each time a notebook is loaded (:exclamation: the kernel should not be running for this to happen).

How is this implemented;

We create a JupyterDash subclass which extends the "inline" visualization capabilities with the functionality described above.
This extension is triggered when *"inline_persistent" *is used in the FigureResampler.show_dash method

• we add a unique _uid to each object
• we add a new endpoint to the underlying flask app that
  1. is only accessible via the corresponding app its _uid
  2. hasCORS rights for any origin and 'Content-Type' headers
     Note that this is the only CORS endpoint of the JupyterDash app & is only preset when "inline_persistent" is used!
• we check in the JavaScript output of the notebook cell whether that endpoint is reachable and emits the expected message (i.e., "Alive")
  • if check is successful => display an iframe of the running Jupyter dash app
  • if check is not successful => display a static image

[codecov-commenter]

Codecov Report

Merging #105 (bc0aabc) into main (c8de84b) will decrease coverage by 0.30%.
The diff coverage is 90.00%.

@@            Coverage Diff             @@
##             main     #105      +/-   ##
==========================================
- Coverage   97.94%   97.63%   -0.31%     
==========================================
  Files          10       10              
  Lines         777      804      +27     
==========================================
+ Hits          761      785      +24     
- Misses         16       19       +3     

Impacted Files	Coverage Δ
...tly_resampler/figure_resampler/figure_resampler.py	89.10% <90.00%> (-0.09%)	⬇️

Help us with your feedback. Take ten seconds to tell us how you rate us.

[jvdd]

@jonasvdd, if you're not keen on adding kaleido as dependency I can look into serializing the figure into html and render this instead when the dash app is not reachable

[jonasvdd]

LGTM, just the kaleido and the docs, but the latter can be tackled in #104

[jonasvdd]

Can this be made optional?

[jonasvdd]

The only places we interact with kaleido is in pyproject.toml (and the underlying plotly code). So this can be made optional i.m.o. and we should just document this properly in our docs. #104

[jonasvdd]

added it as a dev dependency and updated the docs of the FigureResampler.show_dash