html map not showing in rmarkdown report

[Jonw]

Hello,
I have created an html map saved using saveWidget. I have created an html rmarkdown profile that includes the html map. When I open the profile within my work environment, the map shows. When I send the profile outside my work environment the map does NOT show. The space where the map should be is empty and does not show any of the markers either.
I am using Leaflet v2.2.0 to create the map and htmlwidgets v1.6.2 to save it.
Rmarkdown is v2.25
Does anyone know why this might be?
Many thanks

[jlacko]

It is possible that "the other computer" is missing some resources; do check the value of selfcontained in your htmlwidgets::saveWidget() call.

In case of leaflet maps check whether the other computer has internet access - this is required for basemaps functionality; offline / firewalled computer will show a blank space instead of a basemap.

[Jonw]

Thank you @jlacko,
selfcontained is defaulted to TRUE. I can only assume a Firewall issue as the other computers will be connected to the internet. But they can see everything except the map and the report is also html.
Regards

[jlacko]

Can "the other computers" display a different leaflet map? one known to work? so that you could tell whether it is a general leaflet error, or one specific to your widget?

A funny firewall related problem that I have faced in the past was with this walkthru: Leaflet Map Markers in R · Jindra Lacko - the blog post shows several tricks with leaflet markers, one of which is displaying company icon in place of registered headquarters. Since the icon is taken from homepage, and one of the companies listed is Facebook (oh horror!) the last map is known to misbehave in firewalled environments

[Jonw]

Thank you @jlacko, just checked sending the leaflet map on its own to other computers works ok - they can see it. It's only when it's embedded in the rmarkdown report it doesn't show.
Useful link you sent.
Thanks