How do I display a shinyalert pop-up while loading data in R shiny?

Question

I'am working on a pretty "big" dataset that takes at least 20 seconds to be read entirely at the launch of my Shiny app. I would like to display a pop-up waiting message like the one below during this reading time, which will close automatically when it is done.

However, I have no idea how to specify a condition to automatically close the alert. Below what I have done so far :

server <- function(input, output, session) {
   data =read_sav("BS.SAV")
 shinyalert(
      title = "Wait",
      text = "Waiting for data loading",
      size = "xs",
      closeOnEsc = TRUE,
      closeOnClickOutside = TRUE,
      html = TRUE,
      type = "info",
      showConfirmButton = TRUE,
      confirmButtonText = "OK",
      confirmButtonCol = "#004192",
      showCancelButton = FALSE,
      imageUrl = "",
      animation = TRUE
    )
}

score 1 · Accepted Answer · answered Jul 22 '23 at 07:39

Here is one example. The alert can be closed using CloseAlert(). The .csv is a reactive which gets read by a fileInput. We use a custom click handler in order to check whether the fileInput button gets clicked. The output gets then rendered into a DT::datatable and when this object is finally rendered, the alert gets closed.

library(shiny)
library(shinyalert)

options(shiny.maxRequestSize = 30 * 1024 ^ 2 * 2)

js <- HTML(
    "
$(function() {
  $('.shiny-input-container .input-group-btn .btn').on('click', function() {
     const id = $(this).find('input[type=\"file\"]').attr('id');
     Shiny.setInputValue(id + '_click', Math.random());
  })
})"
)

shinyApp(
    ui = fluidPage(
        singleton(tags$head(tags$script(js))),
        fileInput(
            inputId = 'file',
            label = 'Choose CSV File',
            accept = c('text/csv',
                       'text/comma-separated-values,text/plain',
                       '.csv')
        ),
        DT::dataTableOutput("table")
    ),
    
    server = function(input, output, session) {
        input_file <- reactive({
            if (is.null(input$file)) {
                return("")
            }
            
            read.csv(file = input$file$datapath)
        })
        
        
        output$table <- DT::renderDataTable({
            req(input_file())
            
            closeAlert()
            
            input_file()
        })
        
        observeEvent(input$file_click,
                     {
                         shinyalert(
                             title = "Wait",
                             text = "Waiting for data loading",
                             size = "xs",
                             closeOnEsc = TRUE,
                             closeOnClickOutside = TRUE,
                             html = TRUE,
                             type = "info",
                             showConfirmButton = TRUE,
                             confirmButtonText = "OK",
                             confirmButtonCol = "#004192",
                             showCancelButton = FALSE,
                             imageUrl = "",
                             animation = TRUE
                         )
                         
                     },
                     ignoreNULL = FALSE,
                     ignoreInit = TRUE)
    }
)

How do I display a shinyalert pop-up while loading data in R shiny?

1 Answers1