R works with in memory data, so your file needs to be loaded in order for R been able to manipulate it, I don't think that there is a way for a shiny app to manipulate a file that is still in the client's hard drive.
R works with in memory data, so your file needs to be loaded in order for R been able to manipulate it, I don't think that there is a way for a shiny app to manipulate a file that is still in the client's hard drive.