Hide all others markers in Leaflet map when some markers are highlighted through other widgets

[oude-gao]

Hi! Just started using this package, and am trying to combine leaflet with plotly/datatable in a shiny app. The main functionality would be highlighting markers on the leaflet map and see the locations by selecting the points in the plotly scatterplot. However, it's a fairly dense map so even with the other markers dimmed, it's still hard to locate the highlighted ones.

I went into the back-end and found out when highlighting some markers, their opacity/fillOpacity remains the original value, with these two attributes divided by 5 in value to achieve the 'dimming' effect. Is this behavior imported by the leaflet API or crosstalk? It would be great to change it to just giving both attributes a 0 (like what plotly did with the dimOpacity attributes in their highlight function). I couldn't find anything relevant and thought this would be the best place to sought help.

Thanks!!

[tedmoorman]

I think this issue is exactly the same one I'm having. My leaflet map is covered with markers, circles, whatever. I'm currently using R's reactable package to display a table to use for filtering, but the DT package would probably produce the same issue. When I select a single row, I still see too many markers on the map, even though the opacity of the unselected markers is reduced. I would like for all the markers to disappear except for the ones I've chose from the table. Maybe there's a quick fix from leaflet or reactable. But from @oude-gao, it sounds like the ball is in crosstalk's court. Just to be thorough, I will cross reference this in reactable and leaflet. It's definitely deserving of attention.

[tedmoorman]

Reactable developer seemed to think that this was a leaflet issue:

glin commented Feb 14, 2021 Hi, I think this is most likely a leaflet thing. reactable only interacts with leaflet through Crosstalk, and doesn't do anything specific for leaflet. Other Crosstalk examples with leaflet seem to work the same too, like at https://rstudio.github.io/crosstalk/index.html. There may be some config option in leaflet to control the unselected marker opacity, so I'd guess the leaflet repo is the best place to ask about it.

Thoughts?