为什么 input$tableid_all_rows (DT) 在 Shiny 中工作？

Question

I have the following app:

...
              selectInput("cars", "Pick a Car: ",
                          c("All" = "All Cars",
                            "Ford" = "Ford",
                            "Volvo" = "Volvo",
                            "Ferrari" = "Ferrari",
                            "Fiat" = "Fiat",
                            "Merc" = "Merc"))
      )),

    shinySaveButton("save", "Save file", "Save file as ...", filetype=list(csv="csv")),
    DT::dataTableOutput('table1')
      )
    )

# Define server logic required to draw a histogram
server <- function(input, output, session) {

  mtcars$car <- rownames(mtcars)

  output$table1 <-renderDataTable({
    mtcars %>%
      filter(stringr::str_detect(car, as.character(input$cars)) | input$cars == 'All Cars')
    })

  observe({
    volumes <- c("UserFolder"="~/Documents/R1/DwnLdWord/saves")
    shinyFileSave(input, "save", roots=volumes, session=session)
    fileinfo <- parseSavePath(volumes, input$save)
    data <- input$table1_rows_all
    if (nrow(fileinfo) > 0) {
      write.csv(data, fileinfo$datapath)
    }
  })
}
# Run the application 
shinyApp(ui = ui, server = server)

When I save a static dataset (like iris or mtcars ) the file saves the actual data. However, as can be seen in the images, i am wanting to save the contents of the filtered DT.

I thought that is what input$tableid_rows_all was for, but I only get random integer/numeric values. I have always had trouble with this nonsense but I would really like to get it to work because it is such a valuable function.

Help?

Answer 1

Check this:

server <- function(input, output, session) {

  mtcars$car <- rownames(mtcars)

  output$table1 <-renderDataTable({
    mtcars %>%
      filter(stringr::str_detect(car, as.character(input$cars)) | input$cars == 'All Cars')
    })

  observe({
    volumes <- c("UserFolder"="~/Documents/R1/DwnLdWord/saves")
    shinyFileSave(input, "save", roots=volumes, session=session)
    fileinfo <- parseSavePath(volumes, input$save)
     data <- mtcars[input$table1_rows_selected,]
    if (nrow(fileinfo) > 0) {
      write.csv(data, fileinfo$datapath)
    }
  })
}
# Run the application 
shinyApp(ui = ui, server = server)

1. You wanna use rows_selectd because rows_all gives you back all rows in your table
2. You need to substitute tableId by the name of your table ( table1 ) for you
3. You are not getting gibberish, but the index/row number of those rows you have selected (in your case, all)
4. To retrieve all data instead of row number, you need to mtcars[input$table1_rows_selected,]

I hope this does the trick for you. Best!