drop-down checkbox input in shiny

EDIT : This function (and others) is available in package shinyWidgets

---

Hi I wrote this dropdownButton function once, it create a bootstrap dropdown button (doc here), the results looks like :

Here is the code :

# func --------------------------------------------------------------------

dropdownButton <- function(label = "", status = c("default", "primary", "success", "info", "warning", "danger"), ..., width = NULL) {

  status <- match.arg(status)
  # dropdown button content
  html_ul <- list(
    class = "dropdown-menu",
    style = if (!is.null(width)) 
      paste0("width: ", validateCssUnit(width), ";"),
    lapply(X = list(...), FUN = tags$li, style = "margin-left: 10px; margin-right: 10px;")
  )
  # dropdown button apparence
  html_button <- list(
    class = paste0("btn btn-", status," dropdown-toggle"),
    type = "button", 
    `data-toggle` = "dropdown"
  )
  html_button <- c(html_button, list(label))
  html_button <- c(html_button, list(tags$span(class = "caret")))
  # final result
  tags$div(
    class = "dropdown",
    do.call(tags$button, html_button),
    do.call(tags$ul, html_ul),
    tags$script(
      "$('.dropdown-menu').click(function(e) {
      e.stopPropagation();
});")
  )
  }

And an example :

# app ---------------------------------------------------------------------

library("shiny")
ui <- fluidPage(
  tags$h1("Example dropdown button"),
  br(),
  fluidRow(
    column(
      width = 6,
      dropdownButton(
        label = "Check some boxes", status = "default", width = 80,
        checkboxGroupInput(inputId = "check1", label = "Choose", choices = paste(1:26, ") Choice ", LETTERS))
      ),
      verbatimTextOutput(outputId = "res1")
    ),
    column(
      width = 6,
      dropdownButton(
        label = "Check some boxes", status = "default", width = 80,
        actionButton(inputId = "a2z", label = "Sort A to Z", icon = icon("sort-alpha-asc")),
        actionButton(inputId = "z2a", label = "Sort Z to A", icon = icon("sort-alpha-desc")),
        br(),
        actionButton(inputId = "all", label = "(Un)select all"),
        checkboxGroupInput(inputId = "check2", label = "Choose", choices = paste(1:26, ") Choice ", LETTERS))
      ),
      verbatimTextOutput(outputId = "res2")
    )
  )
)
server <- function(input, output, session) {
  output$res1 <- renderPrint({
    input$check1
  })

  # Sorting asc
  observeEvent(input$a2z, {
    updateCheckboxGroupInput(
      session = session, inputId = "check2", choices = paste(1:26, ") Choice ", LETTERS), selected = input$check2
    )
  })
  # Sorting desc
  observeEvent(input$z2a, {
    updateCheckboxGroupInput(
      session = session, inputId = "check2", choices = paste(26:1, ") Choice ", rev(LETTERS)), selected = input$check2
    )
  })
  output$res2 <- renderPrint({
    input$check2
  })
  # Select all / Unselect all
  observeEvent(input$all, {
    if (is.null(input$check2)) {
      updateCheckboxGroupInput(
        session = session, inputId = "check2", selected = paste(1:26, ") Choice ", LETTERS)
      )
    } else {
      updateCheckboxGroupInput(
        session = session, inputId = "check2", selected = ""
      )
    }
  })
}
shinyApp(ui = ui, server = server)

In bonus I put the ascending/descending sorting thingy in the second dropdown buttons.

EDIT Mar 22 ’16

To split yours checkboxes into multiple columns you can do the split yourself with fluidRow and columns and multiples checkboxes, you just have to bind the values server-side.
To implement scrolling put your checkboxes into a div with style="overflow-y: scroll; height: 200px;".

Look at this example :

library("shiny")
ui <- fluidPage(
  tags$h1("Example dropdown button"),
  br(),
  fluidRow(
    column(
      width = 6,
      dropdownButton(
        label = "Check some boxes", status = "default", width = 450,
        tags$label("Choose :"),
        fluidRow(
          column(
            width = 4,
            checkboxGroupInput(inputId = "check1a", label = NULL, choices = paste0(1:10, ") ", LETTERS[1:10]))
          ),
          column(
            width = 4,
            checkboxGroupInput(inputId = "check1b", label = NULL, choices = paste0(11:20, ") ", LETTERS[11:20]))
          ),
          column(
            width = 4,
            checkboxGroupInput(inputId = "check1c", label = NULL, choices = paste0(21:26, ") ", LETTERS[21:26]))
          )
        )
      ),
      verbatimTextOutput(outputId = "res1")
    ),
    column(
      width = 6,
      tags$style(".container { border:2px solid steelblue; width: 100%; height: 200px; overflow-y: scroll; }"),
      dropdownButton(
        label = "Check some boxes", status = "default", width = 120,
        tags$div(
          class = "container",
          checkboxGroupInput(inputId = "check2", label = "Choose", choices = paste0(1:26, ") ", LETTERS))
        )
      ),
      verbatimTextOutput(outputId = "res2")
    )
  )
)
server <- function(input, output, session) {

  valuesCheck1 <- reactiveValues(x = NULL)
  observeEvent(input$check1a, valuesCheck1$x <- unique(c(valuesCheck1$x, input$check1a)))
  observeEvent(input$check1b, valuesCheck1$x <- unique(c(valuesCheck1$x, input$check1b)))
  observeEvent(input$check1c, valuesCheck1$x <- unique(c(valuesCheck1$x, input$check1c)))

  output$res1 <- renderPrint({
    valuesCheck1$x
  })

  output$res2 <- renderPrint({
    input$check2
  })

}
shinyApp(ui = ui, server = server)