Is there an event for cleaning up cell JavaScript on cell re-execution or cell deletion?

ballingt · February 1, 2020, 3:28pm

If I’m rendering some JavaScript in Jupyter Notebook cell that schedules some code to run over and over with setInterval, adds a window-level event listener, etc., I’d like to be sure to cancel the setInterval, remove the event listener, etc. when the cell is re-executed or deleted.

Is there an API like this? Any advice on creating one, e.g. are there class names that are part of the API that I should build out this event around with a MutationObserver?

Edit: I wonder if this event should fire for collapsing cell outputs? I’ll say no for now.

Thanks!

ballingt · February 1, 2020, 8:18am

I threw together some JavaScript that just notices two cases, cell reexecution and cell deletion. Any ideas for more times you might want resources used to render a cell be freed up?

gist.github.com

https://gist.github.com/thomasballinger/2c9718defa7c89daae163b6470a81f8b

cell_invalidation.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "application/javascript": [

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ballingt · February 5, 2020, 6:27am

I made a repo for this to clarify the question: https://github.com/thomasballinger/jupyter-invalidation/blob/2e269d03ad6448227afb319a1b36f566765131ce/example.ipynb

The repo includes an npm module that works as long as it has time to load before other JavaScript that uses it runs. I need to learn a bit more about writing JS in notebooks. https://www.npmjs.com/package/jupyter-invalidation