Shiny app that transfer files - shiny

Question

I am trying to make a very simple app that transfers a user selected file to a fixed location. Then prints the results of the transfer (True / False). The syntax for copying is working outside of shiny
library(shiny)
ui <- fluidPage(
fileInput('file1', 'Choose 1st File',
accept=c('text/csv',
'text/comma-separated-values,text/plain',
'.fastq' , '.fasta')) ,
renderText('result')
)
server <- function(input , output){
output$result <- renderPrint({
file.copy(from = input$file1$datapath,
to = 'H:/Shiny/FileTransfer/TestLocation',
recursive = FALSE,
copy.mode = TRUE)
})
}
shinyApp(ui = ui , server = server)

Answer 1

There are 2 problems with your code. 1) The renderPrint function is never executed, use verbatimTextOutput instead. 2) The file name in $datapath is different from the original file, you should indicate the original name that is in $name, otherwise the destination file will have a name like 0 or some random number.
Below is your code modified with some extra information that could be useful for you. The function file.path is used to indicate the destination directory in addition with the original file name.
library(shiny)
ui <- fluidPage(
fileInput('file1', 'Choose 1st File',
accept=c('text/csv',
'text/comma-separated-values,text/plain',
'.fastq' , '.fasta')) ,
verbatimTextOutput('result')
)
server <- function(input , output){
destDir <- 'H:/Shiny/FileTransfer/TestLocation'
output$result <- renderPrint({
inFile <- input$file1
if (is.null(inFile)) {
cat("NOT FILE\n")
return(FALSE)
}
cat("Reading file:", inFile$name, "\n")
cat("size:", inFile$size, " Bytes, type:", inFile$type, "\n")
if (dir.exists(destDir)){
cat("Copying file to:", destDir,"\n")
result <- file.copy( inFile$datapath,
file.path(destDir, inFile$name) )
} else {
result <- FALSE
}
result
})
}
shinyApp(ui = ui , server = server)