Download two table in two panel with one download button in R shiny

Question

I am using the download button in R shiny, is it possible to download two different tables in different tabPanel(Page A and Page B)?

I think my problem is: If I can let the server know which tab is selected by the user? and then ther server will change the table of the download button based on the tab page.

I can not zip the two table into an excel because the user want the two table to be seperated.

Thanks for your help.

If the user is in page A: export output_batch_predict.xlsx

If the user is in page B: export part.xlsx

This is the code for the download button:

ui:

tabPanel(HTML("<span style='font-size:120%'>Page A</span>"),        
      h4("Table is shown below: ",style="font-size: 20px"),
      helpText("The ** sign means the sample size is less than 5.",style="font-size:16px"),
      h3("Demand no. - based.",style="font-size:16px"),
      h3("Demand rate - based.",style="font-size:16px"),),

tabPanel(HTML("<span style='font-size:120%'>Table_inquire</span>"),
     h4("Table is shown below: ",style="font-size: 20px"),
     h3("Demand no. - based.",style="font-size:16px"),
     h3("Demand rate - based.",style="font-size:16px"),
     h3("Recommended model:",style="font-size:16px"),),


server:
  output$download_predict_batch <- downloadHandler(
filename = function() {
  paste("output_batch_predict.xlsx")
},
content = function(file) {
  dataset_names <- list('Demand no. - based.' = output_table_predict, 'Demand rate - based.' = output_table_predict)
  write.xlsx(dataset_names, file, rowNames = FALSE)
  
}

)

Answer 1

Sure could you use one download button to download tables from different tab panels. Below is a minimal reproducible example on how to achieve that. First you have to add an id to the tabsetPanel. Second, for convenience add a value to the tabPanels to identify which tab is selected. Inside the server you could then use two reactives to set the filename and the data to be exported depending on which tab is selected:

library(shiny)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      downloadButton("download_predict_batch", "Download")
    ),
    mainPanel(
      tabsetPanel(
        id = "tabs",
        tabPanel(
          HTML("<span style='font-size:120%'>Page A</span>"),
          h4("Table is shown below: ", style = "font-size: 20px"),
          value = "tab1"
        ),
        tabPanel(
          HTML("<span style='font-size:120%'>Table_inquire</span>"),
          h4("Table is shown below: ", style = "font-size: 20px"),
          value = "tab2"
        )
      )
    )
  )
)

server <- function(input, output, session) {
  fn <- reactive({
    if (input$tabs == "tab1") {
      "output_batch_predict.xlsx"
    } else {
      "part.xlsx"
    }
  })

  dataset_names <- reactive({
    if (input$tabs == "tab1") {
      list("Demand no. - based." = mtcars, "Demand rate - based." = mtcars)
    } else {
      list("Demand no. - based." = iris, "Demand rate - based." = iris)
    }
  })

  output$download_predict_batch <- downloadHandler(
    filename = function() {
      fn()
    },
    content = function(file) {
      openxlsx::write.xlsx(dataset_names(), file, rowNames = FALSE)
    }
  )
}

shinyApp(ui, server)
#> 
#> Listening on http://127.0.0.1:4685