Demo of new `checkboxGroupInput()` and `radioButtons()` functionality in Shiny 1.0.1

checkbox-choiceNames-flags.R

library(shiny)

countries <- c("Australia", "United Kingdom", "United States")

flags <- c(
  "https://cdn.rawgit.com/lipis/flag-icon-css/master/flags/4x3/au.svg",
  "https://cdn.rawgit.com/lipis/flag-icon-css/master/flags/4x3/gb.svg",
  "https://cdn.rawgit.com/lipis/flag-icon-css/master/flags/4x3/us.svg"
)

ui <- fluidPage(
  checkboxGroupInput("countries", "Countries",
    choiceNames = mapply(countries, flags, FUN = function(country, flagUrl) {
      tagList(
        tags$img(src=flagUrl, width=20, height=15),
        country
      )
    }, SIMPLIFY = FALSE, USE.NAMES = FALSE),
    choiceValues = countries
  ),
  textOutput("txt")
)

server <- function(input, output, session) {
  output$txt <- renderText({
    paste("You chose", paste(input$countries, collapse = ", "))
  })
}

shinyApp(ui, server)