R Shiny - Generating PDF report
<p>I need to generate and download a PDF report from a shiny app. I've found this (I've placed the app.R and report.Rmd files in the same folder):</p>

<p><a href="https://shiny.rstudio.com/articles/generating-reports.html" rel="nofollow noreferrer">https://shiny.rstudio.com/articles/generating-reports.html</a></p>

<pre><code>shinyApp(
ui = fluidPage(
sliderInput("slider", "Slider", 1, 100, 50),
downloadButton("report", "Generate report")
),
server = function(input, output) {
output$report &lt;- downloadHandler(
  # For PDF output, change this to "report.pdf"
  filename = "report.html",
  content = function(file) {
    # Copy the report file to a temporary directory before processing it, in
    # case we don't have write permissions to the current working dir (which
    # can happen when deployed).
    tempReport &lt;- file.path(tempdir(), "report.Rmd")
    file.copy("report.Rmd", tempReport, overwrite = TRUE)

    # Set up parameters to pass to Rmd document
    params &lt;- list(n = input$slider)

    # Knit the document, passing in the `params` list, and eval it in a
    # child of the global environment (this isolates the code in the document
    # from the code in this app).
    rmarkdown::render(tempReport, output_file = file,
      params = params,
      envir = new.env(parent = globalenv())
    )
  }
)
}
)

report.Rmd:

---
title: "Dynamic report"
output: html_document
params:
n: NA
---

```{r}
# The `params` object is available in the document.
params$n
```

A plot of `params$n` random points.
</code></pre>

<p>The problem is, when I run it and press download, I get the following error:</p>

<pre><code>Warning in normalizePath(path.expand(path), winslash, mustWork) :
path[1]="C:\Users\*\AppData\Local\Temp\Rtmp0SaXzj\report.Rmd": Das      System kann die angegebene Datei nicht finden
Warning: Error in tools::file_path_as_absolute: file 'C:\Users\*\AppData\Local\Temp\Rtmp0SaXzj\report.Rmd' does not exist
Stack trace (innermost first):
57: tools::file_path_as_absolute
56: dirname
55: setwd
54: rmarkdown::render
53: download$func [#255]
 4: &lt;Anonymous&gt;
 3: do.call
 2: print.shiny.appobj
 1: &lt;Promise&gt;
Error : file 'C:\Users\*\AppData\Local\Temp\Rtmp0SaXzj\report.Rmd' does not exist
</code></pre>

<p>After a bit of checking I've seen that the copy step does not work, with the error:</p>

<pre><code>file.copy("report.Rmd", "/test/report.Rmd")
&gt;FALSE
</code></pre>

<p>On one hand I think the problem is I am not in the correct folder, and on the other that I can't access the tempDir.</p>

<p>Any ideas?</p>