Getting File Path from Shiny UI (Not Just Directory) Using Browse Button Without Uploading the File

Getting file path from Shiny UI (Not just directory) using browse button without uploading the file

This functionality is available in the shinyFiles package. Have a look at this minimal example:

library(shiny)
library(shinyFiles)
  
  
  ui <- fluidPage(
    shinyFilesButton("Btn_GetFile", "Choose a file" ,
                                    title = "Please select a file:", multiple = FALSE,
                          buttonType = "default", class = NULL),
                   
              textOutput("txt_file")     
                   )

  
  server <- function(input,output,session){
    
    volumes = getVolumes()
    observe({  
    shinyFileChoose(input, "Btn_GetFile", roots = volumes, session = session)
    
    if(!is.null(input$Btn_GetFile)){
      # browser()
      file_selected<-parseFilePaths(volumes, input$Btn_GetFile)
      output$txt_file <- renderText(as.character(file_selected$datapath))
    }
  })
  }
  shinyApp(ui = ui, server = server)

Specify destination folder for download from an R Shiny app

You're passing reactive(file <- input$file1) as the contentType argument to downloadHandler(), which can't be good. Also, you're not writing anything to the file given as an argument to the content function.

Remove the reactive(file <- input$file1) line, and specify output_file = file in rmarkdown::render(), and your download should work.

As discussed in the comments, you won't be able to have control over the download path though -- that's something the user's web browser and their settings there will decide.

Here's a somewhat more minimal app with a functioning file download, for reference:

library(shiny)

ui <- fluidPage(
  sliderInput("value", "Some value", 1, 5, 2),
  downloadButton("report", "Generate report")
)

server <- function(input, output) {
  output$report <- downloadHandler(
    filename = "wordreport.doc",
    content = function(file) {
      params <- list(value = input$value)
      rmarkdown::render(
        system.file("examples/knitr-minimal.Rmd", package = "knitr"),
        output_file = file,
        params = params,
        envir = new.env(parent = globalenv())
      )
    }
  )
}

shinyApp(ui, server)

Is there an equivalent to the Shiny fileInput function for saving outputs?

You can use downloadButton in ui and downloadHandler in server as follows:

library(shiny)

ui <- fluidPage(
        sidebarLayout(
                sidebarPanel(
                        fileInput("file1", "Choose CSV file to upload", accept = ".csv"),
                        checkboxInput("header", "Header", TRUE),
                        downloadButton("download")
                ),
                mainPanel(
                        tableOutput("contents"),
                )
        )
)

server <- function(input, output) {
        output$contents <- renderTable({
                file <- input$file1
                ext <- tools::file_ext(file$datapath)
                
                req(file)
                validate(need(ext == "csv", "Please upload a csv file"))
                
                read.csv(file$datapath, header = input$header)
        })
        
        output$download <- downloadHandler(
                filename = function() {
                        paste0(input$file1, ".csv")
                },
                content = function(file) {
                        write.csv(contents(), file)
                }
        )
}

shinyApp(ui, server)

---

Related Topics