Change the value of a radio input on the client

Source: R/update-input.R

Change the value of a radio input on the client

updateRadioButtons(
  session = getDefaultReactiveDomain(),
  inputId,
  label = NULL,
  choices = NULL,
  selected = NULL,
  inline = FALSE,
  choiceNames = NULL,
  choiceValues = NULL
)

Arguments

session

The session object passed to function given to shinyServer. Default is getDefaultReactiveDomain().

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). If this argument is provided, then choiceNames and choiceValues must not be provided, and vice-versa. The values should be strings; other types (such as logicals and numbers) will be coerced to strings.

selected

The initially selected value. If not specified, then it defaults to the first item in choices. To start with no items selected, use character(0).

inline

If TRUE, render the choices inline (i.e. horizontally)

choiceNames, choiceValues

List of names and values, respectively, that are displayed to the user in the app and correspond to the each choice (for this reason, choiceNames and choiceValues must have the same length). If either of these arguments is provided, then the other must be provided and choices must not be provided. The advantage of using both of these over a named list for choices is that choiceNames allows any type of UI object to be passed through (tag objects, icons, HTML code, ...), instead of just simple text. See Examples.

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

radioButtons()

Examples

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

ui <- fluidPage(
  p("The first radio button group controls the second"),
  radioButtons("inRadioButtons", "Input radio buttons",
    c("Item A", "Item B", "Item C")),
  radioButtons("inRadioButtons2", "Input radio buttons 2",
    c("Item A", "Item B", "Item C"))
)

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

    # Can also set the label and select items
    updateRadioButtons(session, "inRadioButtons2",
      label = paste("radioButtons label", x),
      choices = x,
      selected = x
    )
  })
}

shinyApp(ui, server)
}