reactive text in download handler filename argument

[Ian Kyle]

I've written a shiny app that allows a user to download data.frame, either in .csv or .xls (using the WriteXLS package). When I set the default file type choice (input$format) to '.xls', the file extension and file are .xls. If I then select '.csv', a .csv file is downloaded but the file extension is still .xls. Same if I set selected='.csv' (the file always downloads with .csv extension, but the file may actually be a .xls or .csv depending on what format is selected. 

Why wont the filename register that input$format has changed within the download handler? If I print the value of input$format in the UI, the value changes when I change radiobutton selections. 

# Server

  output$download_data <- downloadHandler(    

                filename = paste0("longdataset_", Sys.time(), input$format),

                        content = function(file){

                          if(input$format=='.csv'){

                        write.csv(data(), file, row.names=FALSE,

                                  na='')}

                          if(input$format=='.xls'){

                            sdat <- data()

                            WriteXLS('sdat',

                                     file)

                          }}

                          )

# UI

radioButtons('format', 'File type:', 

                   choices=c('.xls',

                            '.csv'),

                    selected='.xls'),

      downloadButton('download_data', 'Download long dataset')

[Vincent Nijs]

I have something similar in my app (see below) and it works fine (i.e., file extensions are changed). Your 'filename' line is missing 'function() { ... }'

output$downloadData <- downloadHandler(

  filename = function() { paste(input$datasets,'.',input$saveAs, sep='') },

  content = function(file) { ...

[Ian Kyle]

perfect. thanks!