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?
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)."