Making rgl output accessible in Shiny

[dmurdoch]

In regular widget output I can add alt text using code like

widget <- htmlwidgets::prependContent(widget,
tags$p(altText, id = ariaLabelId(elementId),
hidden = NA))

and then have an aria-labelledbyattribute on the rgl canvas to link to this text. However, the prependContent() function warns that it doesn't work in Shiny. Is there something else I can do in my rglwidget() code or the "scaffolding" to create a fixed invisible element to use as alt text? I'd like to have this happen automatically, without requiring the user to do anything but specify altText.

[dmurdoch]

I have a partial answer to this. The rglwidgetOutput function can return a list of elements (I'm using a tagList), and I can put in the <p> element there just as I did with prependContent.

Clearly it would be better to handle things in renderRglwidget instead (or first); I'm still working on that.