Create a select list input control

Create a select list that can be used to choose a single or multiple items from a list of values.

selectInput(
  inputId,
  label,
  choices,
  selected = NULL,
  multiple = FALSE,
  selectize = TRUE,
  width = NULL,
  size = NULL
)

selectizeInput(inputId, ..., options = NULL, width = NULL)

Arguments

inputId	The input slot that will be used to access the value.
label	Display label for the control, or NULL for no label.
choices	List of values to select from. If elements of the list are named, then that name --- rather than the value --- is displayed to the user. It's also possible to group related inputs by providing a named list whose elements are (either named or unnamed) lists, vectors, or factors. In this case, the outermost names will be used as the group labels (leveraging the <optgroup> HTML tag) for the elements in the respective sublist. See the example section for a small demo of this feature.
selected	The initially selected value (or multiple values if multiple = TRUE). If not specified then defaults to the first value for single-select lists and no values for multiple select lists.
multiple	Is selection of multiple items allowed?
selectize	Whether to use selectize.js or not.
width	The width of the input, e.g. '400px', or '100%'; see validateCssUnit().
size	Number of items to show in the selection box; a larger number will result in a taller box. Not compatible with selectize=TRUE. Normally, when multiple=FALSE, a select input will be a drop-down list, but when size is set, it will be a box instead.
...	Arguments passed to selectInput().
options	A list of options. See the documentation of selectize.js for possible options (character option values inside base::I() will be treated as literal JavaScript code; see renderDataTable() for details).

Value

A select list control that can be added to a UI definition.

Details

By default, selectInput() and selectizeInput() use the JavaScript library selectize.js (https://github.com/selectize/selectize.js) instead of the basic select input element. To use the standard HTML select input element, use selectInput() with selectize=FALSE.

In selectize mode, if the first element in choices has a value of "", its name will be treated as a placeholder prompt. For example: selectInput("letter", "Letter", c("Choose one" = "", LETTERS))

Performance note: selectInput() and selectizeInput() can slow down significantly when thousands of choices are used; with legacy browsers like Internet Explorer, the user interface may hang for many seconds. For large numbers of choices, Shiny offers a "server-side selectize" option that massively improves performance and efficiency; see this selectize article on the Shiny Dev Center for details.

Note

The selectize input created from selectizeInput() allows deletion of the selected option even in a single select input, which will return an empty string as its value. This is the default behavior of selectize.js. However, the selectize input created from selectInput(..., selectize = TRUE) will ignore the empty string value when it is a single choice input and the empty string is not in the choices argument. This is to keep compatibility with selectInput(..., selectize = FALSE).

Server value

A vector of character strings, usually of length 1, with the value of the selected items. When multiple=TRUE and nothing is selected, this value will be NULL.

See also

updateSelectInput() varSelectInput()

Other input elements: actionButton(), checkboxGroupInput(), checkboxInput(), dateInput(), dateRangeInput(), fileInput(), numericInput(), passwordInput(), radioButtons(), sliderInput(), submitButton(), textAreaInput(), textInput(), varSelectInput()

Examples

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

# basic example
shinyApp(
  ui = fluidPage(
    selectInput("variable", "Variable:",
                c("Cylinders" = "cyl",
                  "Transmission" = "am",
                  "Gears" = "gear")),
    tableOutput("data")
  ),
  server = function(input, output) {
    output$data <- renderTable({
      mtcars[, c("mpg", input$variable), drop = FALSE]
    }, rownames = TRUE)
  }
)

# demoing group support in the `choices` arg
shinyApp(
  ui = fluidPage(
    selectInput("state", "Choose a state:",
      list(`East Coast` = list("NY", "NJ", "CT"),
           `West Coast` = list("WA", "OR", "CA"),
           `Midwest` = list("MN", "WI", "IA"))
    ),
    textOutput("result")
  ),
  server = function(input, output) {
    output$result <- renderText({
      paste("You chose", input$state)
    })
  }
)
}