title: Display selected folder path in Shiny
body: <p>I want my Shiny app to allow user specify a path to a folder (locally) and <strong>display</strong> the selected path. The following code works but I can't figure out how to hide "character(0)" in verbatimTextOutput until the folder was selected. I tried conditional panel (see commented out in my code) but can't figure out what to use as a condition here (because shinyDirButton is not a standard action button...). Thank you! </p>
  
  <pre><code>library(shiny)
  library(shinyFiles)
  
  # Define UI for application that draws a histogram
  ui &lt;- fluidPage(
  
    # Application title
    mainPanel(
      shinyDirButton("dir", "Input directory", "Upload"),
      #conditionalPanel(
        #condition = "???",
        verbatimTextOutput('dir')
      #)
    )
  )
  
  server &lt;- function(input, output) {
  
    shinyDirChoose(input, 'dir', roots = c(home = '~'), filetypes = c('', 'txt','bigWig',"tsv","csv","bw"))
  
    dir &lt;- reactive(input$dir)
    output$dir &lt;- renderPrint({parseDirPath(c(home = '~'), dir())})
  
    observeEvent(
      ignoreNULL = TRUE,
      eventExpr = {
        input$dir
      },
      handlerExpr = {
        home &lt;- normalizePath("~")
        datapath &lt;&lt;- file.path(home, paste(unlist(dir()$path[-1]), collapse = .Platform$file.sep))
      }
    )
  }
  
  # Run the application 
  shinyApp(ui = ui, server = server)
  </code></pre>
  
  <p>The closest question I was able to find is this but it doesn't solve my problem: <a href="https://stackoverflow.com/questions/17885605/r-conditionalpanel-reacts-to-output">R conditionalPanel reacts to output</a></p>