Can't set 'colorbar' parameters in layout.template.data.{trace}[i].{line|marker}

[wbrgss]

Setting colorbar parameters doesn't appear to work in layout.template.data.{trace_type}[i].{line|marker}.

Related: #3100 (comment), to quote @etpinard:

As for the colorbar part, the problem comes from the colorbar defaults call:

plotly.js/src/components/colorscale/defaults.js

Line 62 in d340150

if(showScale) colorbarDefaults(containerIn, containerOut, layout);

where containerOut is fullData[i] for heatmap, but is fullData[i].marker for scatter and other marker colorscales. Colorbar templates propagate correctly (using Template.newContainer) from fullData[i], but not from marker containers. Adding

should be enough to fix this, but we should look for other situations where supply-defaults subroutines are called with trace sub-containers.

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I'm not sure the above suggested fix was ever implemented.

This codepen demonstrates the issue with ypad:
https://codepen.io/wbrgss/pen/NWPXEPG

I logged a separate issue related to #3100 in #4466

[wbrgss]

To be more specific, I've noticed this for line as well as marker colorscales, including scatter but also parcats and splom.

[etpinard]

Thanks for pointing this out.

I botched 6a47d66 for colorbar containers.

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Please note that line colorscales are not supported in scatter lines (they are in marker.line) and that splom traces only support markers.