Feature: Country colour coding according to filter

[droberts-ctrlo]

We have a specific use-case we are using plotly.js for within the company I work for; we sometimes need to colour-code countries according to specific criterion within a geo map - for example, we may need all predominantly English speaking countries to be Blue, all predominantly French to be green, predominantly Spanish to be yellow, etc.

We have implemented this for our use-case, and wonder if it would be useful for the community; should it be as such, we can open a pull request of our code, and work from there.

[28raining]

Have you tried Choropleth maps?
https://plotly.com/javascript/choropleth-maps/

[alexcjohnson]

Thanks @droberts-ctrlo - I'm curious to hear about what you implemented. From the sound of it I'm guessing you already have a choropleth, and I think what you're adding is a flavor of categorical colorscales #1747. The alternative for this kind of data is to break it into different traces, one per category, and give each trace a fixed color. This is what plotly.express does from the Python side, but we don't have a clean way to construct traces like this purely in JS.