Dropdown menu in R Shiny

Shiny framework use bootstrap 3 that support drop down menus, all you have to do, to have drop down menu in Shiny, is to prepare html and the bootstrap will handle style and logic for opening and closing the menu. Here is the handy function that will create drop down menu for you:

dropdownMenu <- function(label=NULL, icon=NULL, menu=NULL) {
  ul <- lapply(names(menu), function(id) {
    if (is.character(menu[[id]])) {
      tags$li(actionLink(id, menu[[id]]))
    } else {
      args <- menu[[id]]
      args$inputId <- id
      tags$li(do.call(actionLink, args))
  ul$class <- "dropdown-menu"
    class = "dropdown",
      class = "btn btn-default dropdown-toggle",
      type = "button",
      `data-toggle` = "dropdown",
      `if`(!is.null(icon), icon, tags$span(class="caret"))
    do.call(tags$ul, ul)

The function will create drop down menu with caret like on the demo on getbootstrap.com or if you provide icon you will get only that icon the label is optional so you can have dropdown menu with just an icon. It use actionLink to create links so you don't need to to create custom input widget

You can use this function like this, to create hamburger menu:

  icon = icon("bars"),
  menu = list(edit = "edit item", rename = list(label = "address", icon = icon("id-card"))

and it will create two inputs input$edit and input$rename so you can add observeEvent to listen to on click.