Downloading Data description

[mvsell]

I think this page could be more helpful for a beginner like me; https://shiny.rstudio.com/articles/download.html

I don't understand this concept enough to make sense of it, but I wish the statement below would explain by example more than by pointing out a case that doesn't work (I can do that ). What about a case that does work?

"Both the filename and content arguments can use reactive values and expressions (although in the case of filename , if you are using a reactive value, be sure your argument is an actual function; filename = paste(input$dataset, ".csv", sep = "") will not work the way you want it to, since it is evaluated only once, when the download handler is being defined)."

[EconomiCurtis]

Many of these articles do assume familiarity with the mechanics of how shiny works, that is, basics of R, R-function arguments, reactivity, and so on. So I can see how this would be confusing when you're just getting started with these concepts.

If that is the case, the Shiny team created a three-hour intro course on Shiny here: https://shiny.rstudio.com/tutorial/, which is a great place to start. I feel this (with an intro to R, of course), will help make these docs much more useful.

Also, note that all this is documentation for a free and open source tool, so the shiny community is quite welcome to your ideas to improve this documentation.

---

To answer your question, what should this look like? the article gives an example of what this should look like in the code block reproduced below;

  # Downloadable csv of selected dataset ----
  output$downloadData <- downloadHandler(
    filename = function() {
      paste(input$dataset, ".csv", sep = "")
    },
    content = function(file) {
      write.csv(datasetInput(), file, row.names = FALSE)
    }
  )

Note that rpaste(input$dataset, ".csv", sep = "") was placed into a function function(){...}