pickerInput(
  inputId,
  label = NULL,
  choices,
  selected = NULL,
  multiple = FALSE,
  options = list(),
  choicesOpt = NULL,
  width = NULL,
  inline = FALSE
)

## Only run examples in interactive R sessions
if (interactive()) {

# You can run the gallery to see other examples
shinyWidgetsGallery()


# Basic usage
library("shiny")
library(shinyWidgets)

ui <- fluidPage(
  pickerInput(
    inputId = "somevalue",
    label = "A label",
    choices = c("a", "b")
  ),
  verbatimTextOutput("value")
)

server <- function(input, output) {
  output$value <- renderPrint(input$somevalue)
}

shinyApp(ui, server)

}

### Add actions box for selecting ----
### deselecting all options

if (interactive()) {

  library(shiny)
  library(shinyWidgets)

  ui <- fluidPage(
    tags$h2("Select / Deselect all"),
    pickerInput(
      inputId = "p1",
      label = "Select all option",
      choices = rownames(mtcars),
      multiple = TRUE,
      options = list(`actions-box` = TRUE)
    ),
    verbatimTextOutput("r1"),
    br(),
    pickerInput(
      inputId = "p2",
      label = "Select all option / custom text",
      choices = rownames(mtcars),
      multiple = TRUE,
      options = list(
        `actions-box` = TRUE,
        `deselect-all-text` = "None...",
        `select-all-text` = "Yeah, all !",
        `none-selected-text` = "zero"
      )
    ),
    verbatimTextOutput("r2")
  )

  server <- function(input, output, session) {

    output$r1 <- renderPrint(input$p1)
    output$r2 <- renderPrint(input$p2)

  }

  shinyApp(ui = ui, server = server)

}

### Customize the values displayed in the box ----

if (interactive()) {

  library(shiny)
  library(shinyWidgets)

  ui <- fluidPage(
    br(),
    pickerInput(
      inputId = "p1",
      label = "Default",
      multiple = TRUE,
      choices = rownames(mtcars),
      selected = rownames(mtcars)[1:5]
    ),
    br(),
    pickerInput(
      inputId = "p1b",
      label = "Default with | separator",
      multiple = TRUE,
      choices = rownames(mtcars),
      selected = rownames(mtcars)[1:5],
      options = list(`multiple-separator` = " | ")
    ),
    br(),
    pickerInput(
      inputId = "p2",
      label = "Static",
      multiple = TRUE,
      choices = rownames(mtcars),
      selected = rownames(mtcars)[1:5],
      options = list(`selected-text-format`= "static",
                     title = "Won't change")
    ),
    br(),
    pickerInput(
      inputId = "p3",
      label = "Count",
      multiple = TRUE,
      choices = rownames(mtcars),
      selected = rownames(mtcars)[1:5],
      options = list(`selected-text-format`= "count")
    ),
    br(),
    pickerInput(
      inputId = "p3",
      label = "Customize count",
      multiple = TRUE,
      choices = rownames(mtcars),
      selected = rownames(mtcars)[1:5],
      options = list(
        `selected-text-format`= "count",
        `count-selected-text` = "{0} models choosed (on a total of {1})"
      )
    )
  )

  server <- function(input, output, session) {

  }

  shinyApp(ui = ui, server = server)

}

### Limit the number of selections ----

if (interactive()) {

  library(shiny)
  library(shinyWidgets)

  ui <- fluidPage(
    pickerInput(
      inputId = "groups",
      label = "Select one from each group below:",
      choices = list(
        Group1 = c("1", "2", "3", "4"),
        Group2 = c("A", "B", "C", "D")
      ),
      multiple = TRUE,
      options =  list("max-options-group" = 1)
    ),
    verbatimTextOutput(outputId = "res_grp"),
    pickerInput(
      inputId = "groups_2",
      label = "Select two from each group below:",
      choices = list(
        Group1 = c("1", "2", "3", "4"),
        Group2 = c("A", "B", "C", "D")
      ),
      multiple = TRUE,
      options =  list("max-options-group" = 2)
    ),
    verbatimTextOutput(outputId = "res_grp_2"),
    pickerInput(
      inputId = "classic",
      label = "Select max two option below:",
      choices = c("A", "B", "C", "D"),
      multiple = TRUE,
      options =  list(
        "max-options" = 2,
        "max-options-text" = "No more!"
      )
    ),
    verbatimTextOutput(outputId = "res_classic")
  )

  server <- function(input, output) {

    output$res_grp <- renderPrint(input$groups)
    output$res_grp_2 <- renderPrint(input$groups_2)
    output$res_classic <- renderPrint(input$classic)

  }

  shinyApp(ui, server)

}