以 csv 格式下载生成的表格 - R Shiny

Question

My shiny app generates a table that I want to make available for download in a csv format.

  ui = fluidPage( ...
         tableOutput("contents"),
         downloadButton("download", "Download results in csv format") 
)

server <- function( input, output, session ) {
   
   output$contents <- renderTable( ... )
  

output$download <- downloadHandler(
    filename = function() {
      paste(contents, ".csv", sep = "")
    },
    content = function(file) {
      write.csv(contents(), file, row.names = FALSE)
    }
  )

I understand that I have to create a reactive object, but the renderTable itself uses another reactive object (uploaded dataset), so it looks like I need to nest one reactive object into another, and it does not seem to work. Will appreciate any help. Thank you!

Answer 1

EDIT: Added an example using renderTable instead of renderDataTable , as requested by the question and in the comment section:

Here is an example using the iris dataset. I also added a table from the DT package. You should not paste the data in the filename function, only in the in the write.csv function.

```{r}
library(shinydashboard)
library(dplyr)
library(DT)

```
setosa <- filter(iris, Species == "setosa")

ui = fluidPage(
  downloadButton("download", "Download results in csv format") ,
  column(12,
         DT::dataTableOutput ("content"),
         style = "  overflow-y: scroll;overflow-x: scroll;")
  
)

server <- function(input, output, session) {
  output$content <-
    renderDataTable(head(setosa))
  output$download <-
    downloadHandler(
      filename = function () {
        paste("MyData.csv", sep = "")
      },
      content = function(file) {
        write.csv(content, file)
      }
    )
}

shinyApp(ui, server)
```

Using renderTable instead of renderDataTable

library(shiny)
library(dplyr)
library(DT)


setosa <- filter(iris, Species == "setosa")

ui = fluidPage(
  downloadButton("download", "Download results in csv format"),
   tableOutput("table")

  
)

server <- function(input, output, session) {
  data <- data.frame(setosa)
  output$table <-
    renderTable(data)
  output$download <-
    downloadHandler(
      filename = function () {
        paste("MyData.csv", sep = "")
      },
      
      content = function(file) {
        write.csv(data, file)
      }
    )
}

shinyApp(ui, server)