examples/use_busy_spinner.R

In dreamRs/shinybusy: Busy Indicators and Notifications for 'Shiny' Applications

if (interactive()) {
  library(shiny)
  library(shinybusy)

  ui <- fluidPage(

    # Use this function somewhere in UI
    use_busy_spinner(spin = "fading-circle"),

    headerPanel('Iris k-means clustering'),

    sidebarLayout(
      sidebarPanel(
        selectInput('xcol', 'X Variable', names(iris)),
        selectInput('ycol', 'Y Variable', names(iris),
                    selected=names(iris)[[2]]),
        numericInput('clusters', 'Cluster count', 3,
                     min = 1, max = 9),
        actionButton("sleep", "Long calculation")
      ),
      mainPanel(
        plotOutput('plot1')
      )
    )
  )

  server <- function(input, output, session) {

    selectedData <- reactive({
      iris[, c(input$xcol, input$ycol)]
    })

    clusters <- reactive({
      kmeans(selectedData(), input$clusters)
    })

    output$plot1 <- renderPlot({
      palette(c("#E41A1C", "#377EB8", "#4DAF4A", "#984EA3",
                "#FF7F00", "#FFFF33", "#A65628", "#F781BF",
                "#999999"))

      par(mar = c(5.1, 4.1, 0, 1))
      plot(selectedData(),
           col = clusters()$cluster,
           pch = 20, cex = 3)
      points(clusters()$centers, pch = 4, cex = 4, lwd = 4)
    })

    observeEvent(input$sleep, {
      show_spinner()
      Sys.sleep(5)
      hide_spinner()
    })

  }

  shinyApp(ui, server)
}