Changing legend title in a leaflet map in shiny

Question

I have a list of possible coloring options in a map in shiny + leaflet, such as

vars <- c("Difference"  = "diff",
          "Index"       = "index",
          "City Cargo"  = "cid_carga",
          "City score"  = "carga_mun_score")

From the above variables I create a selection list, which will be used to select the desired variable to be colored in the map

selectInput("color", "Color", vars, selected = "carga_mun_score")

However, and obviously, when I create the legend title in the leaflet map, the title stays as the actual name of the variable, e.g., "cid_cargo" instead of "City Cargo".

addLegend("bottomleft",pal = pal, values = df[[input$color]], title = input$color,
                          layerId = "colorLegend")

Is there a way to use my alias (in the example above "city score") name instead of the actual variable name ("carga_mun_score"), without using a really long if clause?

Answer 1

Simply:

addLegend("bottomleft",pal = pal, values = df[[input$color]], 
                          layerId = "colorLegend", title="City Score")

Or save your selection to a variable that can translate the names:

varname<-switch(input$color,
           "diff" = "Difference",
           "index"="Index",
          "cid_carga"="City Cargo",
          "carga_mun_score"="City score")

Then pass that variable to your leaflet legend:

    addLegend("bottomleft",pal = pal, values = df[[input$color]],
                              layerId = "colorLegend", title=varname)