R: Change the value of a select input on the client

updateSelectInput {shiny} | R Documentation

## Change the value of a select input on the client

### Description

Change the value of a select input on the client

### Usage

    updateSelectInput(session, inputId, label = NULL, choices = NULL,
      selected = NULL)

    updateSelectizeInput(session, inputId, label = NULL, choices = NULL,
      selected = NULL, options = list(), server = FALSE)

### Arguments

`session` | The `session` object passed to function given to `shinyServer`.
`inputId` | The id of the input object.
`label` | The label to set for the input object.
`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. This can also be a named list whose elements are (either named or unnamed) lists or vectors. If this is the case, the outermost names will be used as the "optgroup" label for the elements in the respective sublist. This allows you to group and label similar choices. 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.
`options` | A list of options. See the documentation of selectize.js for possible options (character option values inside `I()` will be treated as literal JavaScript code; see `renderDataTable()` for details).
`server` | whether to store `choices` on the server side, and load the select options dynamically on searching, instead of writing all `choices` into the page at once (i.e., only use the client-side version of selectize.js)

### Details

The input updater functions send a message to the client, telling it to change the settings of an input object. The messages are collected and sent after all the observers (including outputs) have finished running.

The syntax of these functions is similar to the functions that created the inputs in the first place. For example, `numericInput()` and `updateNumericInput()` take a similar set of arguments.

Any arguments with NULL values will be ignored; they will not result in any changes to the input object on the client.

For `radioButtons()`, `checkboxGroupInput()` and `selectInput()`, the set of choices can be cleared by using `choices=character(0)`. Similarly, for these inputs, the selected item can be cleared by using `selected=character(0)`.

### See Also

`selectInput`

### Examples

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

    ui <- fluidPage(
      p("The checkbox group controls the select input"),
      checkboxGroupInput("inCheckboxGroup", "Input checkbox",
        c("Item A", "Item B", "Item C")),
      selectInput("inSelect", "Select input",
        c("Item A", "Item B", "Item C"))
    )

    server <- function(input, output, session) {
      observe({
        x <- input$inCheckboxGroup

        # Can use character(0) to remove all choices
        if (is.null(x))
          x <- character(0)

        # Can also set the label and select items
        updateSelectInput(session, "inSelect",
          label = paste("Select input label", length(x)),
          choices = x,
          selected = tail(x, 1)
        )
      })
    }

    shinyApp(ui, server)
    }

[Package shiny version 1.1.0 Index]