A KMZ file is just a zipped KML file, possibly with associated embedded images, icons, etc. So any program that supports KMZ files internally unzips them to access their KML files. That may be a reason why many open source programs do not bother supporting KMZ once KML support is implemented: you just need to use an additional unzipping library of your choice, to convert the KMZ to KML. The linked posts give some JavaScript-based solutions for unzipping.

Resources

These resources are very basic but they may be helpful for me later.

My notes

Example states for shiny-salesman app….

# From http://leafletjs.com/examples/choropleth/us-states.js
# Data Referenced from https://github.com/rstudio/leaflet/tree/master/docs/json/

states <- geojsonio::geojson_read("./json/us-states.geojson", what = "sp")
bins <- c(0, 10, 20, 50, 100, 200, 500, 1000, Inf)
pal <- colorBin("YlOrRd", domain = states$density, bins = bins)
labels <- sprintf(
  "<strong>%s</strong><br/>%g people / mi<sup>2</sup>",
  states$name, states$density
) %>% lapply(htmltools::HTML)
leaflet(states) %>%
  setView(-96, 37.8, 4) %>%
  addProviderTiles("MapBox", options = providerTileOptions(
    id = "mapbox.light",
    accessToken = Sys.getenv('MAPBOX_ACCESS_TOKEN'))) %>%
  addPolygons(
    fillColor = ~pal(density),
    weight = 2,
    opacity = 1,
    color = "white",
    dashArray = "3",
    fillOpacity = 0.7,
    highlight = highlightOptions(
      weight = 5,
      color = "#666",
      dashArray = "",
      fillOpacity = 0.7,
      bringToFront = TRUE),
    label = labels,
    labelOptions = labelOptions(
      style = list("font-weight" = "normal", padding = "3px 8px"),
      textsize = "15px",
      direction = "auto")) %>%
  addLegend(pal = pal, values = ~density, opacity = 0.7, title = NULL,
    position = "bottomright")