How to color a leaflet map by a categorical variable?

Question

Using leaflet, how can I color the different areas based on 'NAME_ASCI' and show colors on a legend?

This works:

library(leaflet)
library(mapview)
m <- leaflet(franconia) %>%
  addProviderTiles("OpenStreetMap") %>%
  addFeatures(.)
m

But when I try to color dynamically it doesn't work. Where the color argument should go?

m <- leaflet(franconia, color = ~ RdYlBu(NAME_ASCI)) %>%
  addProviderTiles("OpenStreetMap") %>%
  addFeatures(.)
m

# With mapview I use 'zcol' to accomplish the colors

mapview(franconia, zcol = "NAME_ASCI")

Answer 1

As a starter I would suggest to have a look at the docs on colors and legends. color is an attribute of the addXXX functions.

library(leaflet)
library(mapview)

colors <- colorRampPalette(
  RColorBrewer::brewer.pal(11, "RdYlBu")
)(length(levels(franconia$NAME_ASCI)))

pal <- leaflet::colorFactor(colors,
  domain = levels(franconia$NAME_ASCI)
)

leaflet(franconia) %>%
  addProviderTiles("OpenStreetMap") %>%
  addPolygons(
    color = ~ pal(NAME_ASCI),
    fillOpacity = 1, stroke = FALSE
  ) %>%
  addLegend(
    pal = pal,
    values = ~NAME_ASCI,
    opacity = 1
  )