shiny progress bar

server.R

library(shiny)
library(shinyIncubator)

shinyServer(function(input, output, session) {
  
  output$out2 <- renderPrint({
    "output 2"
  })
  
  output$plot <- renderPlot({
    withProgress(session, min=1, max=15, {
      setProgress(message = 'Calculation in progress',
                  detail = 'Go and get a coffee :D')
      for (i in 1:15) {
        setProgress(value = i)
        Sys.sleep(0.5)
      }
    })
    plot(cars)
  })
})

ui.R

library(shiny)
library(shinyIncubator)

shinyUI(bootstrapPage(
   progressInit(),
   plotOutput("plot"),
   verbatimTextOutput("out2")
)
)