Pass the argument preloader to the
dashboardPage() function. It expects a nested list
containing all parameters necessary to
waiter::waiterShowOnLoad. Please have a look to the
{waiter} documentation for more
details.
That’s all!
library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
library(waiter)
shinyApp(
  ui = dashboardPage(
    preloader = list(html = tagList(spin_1(), "Loading ..."), color = "#3c8dbc"),
    header = dashboardHeader(),
    sidebar = dashboardSidebar(),
    body = dashboardBody(
      actionButton("reload", "Reload")
    ),
    title = "Preloader"
  ),
  server = function(input, output, session) {
    # fake reload
    observeEvent(input$reload, {
      session$reload()
    })
  }
)