Does scatter_geo needs an internet access to display the map?

[David22]

Plotly actually tries to retrieve data from https://cdn.plot.ly/world_110m.json to plot the map. I found discussions about this on python - Displaying Plotly maps on disconnected system - Stack Overflow, (Kevin Daly’s answer), and here Cannot draw a map offline · Issue #514 · plotly/plotly.py · GitHub (carlosvega’s answer)
Hammy27 suggested that installing plotly-geo would fix the issue, but it didnt work; maps are still missing.

The root of the issue is that the machine on which the dash app run does not have any access to the internet.

Edit:
While looking for a reference to “topojson” somewhere in the doc, in the modules files and on this forum, I found this previous post:

Loading geo assets offline [Solved]

I know this is marked as solved, but since I had a similar issue with trying to do this with Dash, and this is the first link that shows up, I thought I’d share my solution after trying to figure out how to host the files locally, having some iptables or /etc/hosts change that forwarded to my local machine, I eventually tried the “hack” of modifiying the topojsonURL config in my local plotly.min.js file suggest here. However that still didn’t work. I kept getting the same error about not being…

which pointed to the doc:

plotly/plotly.js/blob/master/src/plot_api/plot_config.js

and helped a lot in fixing the problem. Thanks, @zoohair

In a nutshell, the solution consists in:

1. in the DashApp assets folder, make a new folder in which will be stored the topjson files. In this example, I named it “topojson_local”

2. copy-paste the content of https://cdn.plot.ly/world_110m.json, https://cdn.plot.ly/world_110m.json in a json file, which is then saved into the assets/topojson folder. Proceed similarly with https://cdn.plot.ly/world_50m.json, and the other ones.

3. at the top of the dash app, add the following:

   isOffline = True
   plotlyConfig = {'topojsonURL':'assets/topojson_local/'} if isOffline else {}
   

   (as suggested by @zoohair )

4. the dcc.Graph component containing the map must set the config arg as below:

     dcc.Graph(
         id='map-xyz',
         config=plotlyConfig,
         figure=fig,
         style={"height": "100%"}
     )
   

And then, the dash app will render the map, even if it is executed on some intranet without any access to the web.