vgplot: programatically enable/disable

[declann]

Mosaic clients can be programatically enabled/disabled via #721 (example code using IntersectionObserver).

This same control in vgplot would be helpful for dashboard optimisation - so that out -of-view or collapsed charts can be prevented from updating.

[sanghoonio]

I'm not sure if this is a suitable workaround if you wanted to avoid creating custom clients, but I tried this:

1. define a custom API context with separate coordinator for plots or groups of plots you want to hide:

const qcAPI = vg.createAPIContext({
  coordinator: new vg.Coordinator(vg.socketConnector())
});

2. use the API context for your disable-able plot:

const percentMT = qcAPI.plot(
  qcAPI.densityY(qcAPI.from('cells', { filterBy: $densityFilter }), {
    x: 'percent_mt',
    fill: 'sample',
    opacity: 0.25,
    tip: true,
    title: 'sample',
    normalize: 'max',
  }),
  qcAPI.name('percentMT'),
  qcAPI.colorRange(tableau20),
  qcAPI.colorDomain(samples),
  qcAPI.intervalX({ as: $percentMTBrush }),
  qcAPI.xLabel(umapCategories.percent_mt.title),
  qcAPI.yAxis(null),
  qcAPI.width(containerWidth),
  qcAPI.height(88),
);
if (percentMTRef.current) percentMTRef.current.replaceChildren(percentMT);

3. clear the API context whenever you hide the plot and/or on effect cleanup:

useEffect(() => { // plot qc if any dependences change
  if (!showQCDist) return;
  plotQC();
  return () => {
    if (percentMTRef.current) percentMTRef.current.replaceChildren(qcAPI.plot(qcAPI.name('percentMT')));
    qcAPI.context.coordinator.clear({ clients: true, cache: true });
  }
}, [samples, showQCDist]);

...

onClick={() => {
  if (showQCDist) { // reset brushes on hide only
    handleReset();
    if (percentMTRef.current) percentMTRef.current.replaceChildren(qcAPI.plot(qcAPI.name('percentMT')));
    qcAPI.context.coordinator.clear({ clients: true, cache: true });
  }
  setShowQCDist(!showQCDist);
}}

[declann]

That's an interesting workaround Sam - thanks for sharing!

[sanghoonio]

It's pretty brute force because it clears the client of the plot you are hiding (which resets the plot if you want to reenable), but it at least improves selection/query speed of my visible plots by a lot..