shiny-server.R

library(shiny)
ui <- fluidPage(
  titlePanel("Shiny Server"),
  uiOutput("server_update"),
  actionButton(
    "click_button",
    label = "Actualitza botó"
  )
)
server <- function(input, output, session) {
  output$server_update <- renderUI({
    clicks <- input$click_button
    icon_status_up <-
      is.null(clicks) || clicks %% 2 == 0
    icon_name <- if(icon_status_up) {
      "arrow-up"
    } else {
      "arrow-down"
    }
    actionButton(
      "server_update",
      label = "Utilitzo reactivitat del servidor",
      icon = icon(icon_name)
    )
  })
}
shinyApp(ui, server)