Input variables not updating inside downloadHandler for Shiny - r

Question

I am trying to output either a .html or .csv file depending on a radio input button by the user but the input is not updating inside the downloadHandler. It stays on the default value selected.
output$bidownload <- downloadHandler(
if(input$conreport == 'report') {
filename = paste0(input$conreport, '.html')
} else {
filename = paste0(input$conreport, '.csv')
},
content = function(file) {
if(as.character(input$reporttype) == 'report') {
tempReport <- file.path(tempdir(), paste0(input$conreport, '.Rmd'))
file.copy(paste0(input$conreport, '.Rmd'), tempReport, overwrite = TRUE)
params <- list(range = as.character(input$dateparam))
rmarkdown::render(tempReport, output_file = file,
params = params,
envir = new.env(parent = globalenv())
)
} else {
write.csv(weightbreak_raw(), file)
}
}
)
Since the selected radiobutton is on 'report', I will always produce an .html document even if the user changes the radio button. How do I get the input to update in the downloadhandler? I checked here and still cannot figure out how to fix this

Answer 1

downloadHandler filename argument is either a string or a function. If you use a string, it is evaluated at render time but if you use a function it will be evaluated at download time (so after user select the desired type of download) :
output$bidownload <- downloadHandler(
function(){
if(input$conreport == 'report')
paste0(input$conreport, '.html')
else
paste0(input$conreport, '.csv')
},
...