Action button/link — actionButton

actionButton(inputId, label, icon = NULL, width = NULL, ...)

actionLink(inputId, label, icon = NULL, ...)

Arguments

inputId	The input slot that will be used to access the value.
label	The contents of the button or link--usually a text label, but you could also use any other HTML, like an image.
icon	An optional icon() to appear on the button.
width	The width of the input, e.g. '400px', or '100%'; see validateCssUnit().
...	Named attributes to be applied to the button or link.

Description

Creates an action button or link whose value is initially zero, and increments by one each time it is pressed.

Server value

An integer of class "shinyActionButtonValue". This class differs from ordinary integers in that a value of 0 is considered "falsy". This implies two things:

• Event handlers (e.g., observeEvent(), eventReactive()) won't execute on initial load.

• Input validation (e.g., req(), need()) will fail on initial load.

See also

observeEvent() and eventReactive()

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

Examples

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

ui <- fluidPage(
  sliderInput("obs", "Number of observations", 0, 1000, 500),
  actionButton("goButton", "Go!"),
  plotOutput("distPlot")
)

server <- function(input, output) {
  output$distPlot <- renderPlot({
    # Take a dependency on input$goButton. This will run once initially,
    # because the value changes from NULL to 0.
    input$goButton

    # Use isolate() to avoid dependency on input$obs
    dist <- isolate(rnorm(input$obs))
    hist(dist)
  })
}

shinyApp(ui, server)

}