datatableUI<- function(id){
  ns<-NS(id)
  DT::dataTableOutput(ns("dtable"))
}

datatableServer<-function(id, dat){
  moduleServer(
    id,
    function(input,output,session){
      output$dtable<- renderDataTable({
        validate(need(nrow(dat())>0, "No data"))
        datatable(
          dat(),
          extensions = "Buttons",
          options = list(
            paging = TRUE,
            scrollX = TRUE,
            searching = TRUE,
            ordering = TRUE,
            dom = 'Bfrtip',
            buttons = c('copy', 'csv', 'excel', 'pdf'),
            pageLength = 10,
            lengthMenu = c(3, 5, 10)
          )
        )
      })
    }
  )
}