future wrapper does not work with download button

[nvshah286]

I am trying to do async for a download button my shiny app. The file download takes 8-10 seconds so i want to run it in background and make the app available for the users in that time.

I wrapped the download function with future . But it does not work as expected.

script :

output$Report <-
shiny::downloadHandler(

  filename = function(){
    fileName
  },
  content = function(file) {
     params = list(origin =input$Origin,
                   destination = input$Destination)
     # knit the document 
     observe(print(params))
     observe(head(flightsData))
     
     future({
       downloadPpt(fileName = fileName, inputParams = params)
       file.copy(file.path(filePath,fileName),file)
     })

  }   
  
)

[king-of-poppk]

This issue belongs to Shiny, not promises.