Create radio buttons — radioButtons

v1.8.1|Source: R/input-radiobuttons.R

Description

Create a set of radio buttons used to select an item from a list.

radioButtons(
  inputId,
  label,
  choices = NULL,
  selected = NULL,
  inline = FALSE,
  width = NULL,
  choiceNames = NULL,
  choiceValues = 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). 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)

width

The width of the input, e.g. '400px', or '100%'; see validateCssUnit().

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.

Value

A set of radio buttons that can be added to a UI definition.

Details

If you need to represent a "None selected" state, it's possible to default the radio buttons to have no options selected by using selected = character(0). However, this is not recommended, as it gives the user no way to return to that state once they've made a selection. Instead, consider having the first of your choices be c("None selected" = "").

Server value

A character string containing the value of the selected button.

See also

updateRadioButtons()

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

Examples

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

ui <- fluidPage(
  radioButtons("dist", "Distribution type:",
               c("Normal" = "norm",
                 "Uniform" = "unif",
                 "Log-normal" = "lnorm",
                 "Exponential" = "exp")),
  plotOutput("distPlot")
)

server <- function(input, output) {
  output$distPlot <- renderPlot({
    dist <- switch(input$dist,
                   norm = rnorm,
                   unif = runif,
                   lnorm = rlnorm,
                   exp = rexp,
                   rnorm)

    hist(dist(500))
  })
}

shinyApp(ui, server)

ui <- fluidPage(
  radioButtons("rb", "Choose one:",
               choiceNames = list(
                 icon("calendar"),
                 HTML("<p style='color:red;'>Red Text</p>"),
                 "Normal text"
               ),
               choiceValues = list(
                 "icon", "html", "text"
               )),
  textOutput("txt")
)

server <- function(input, output) {
  output$txt <- renderText({
    paste("You chose", input$rb)
  })
}

shinyApp(ui, server)
}