R Shiny - 生成报告

Question

我想从闪亮的应用程序导出html / pdf文件，我发现这个https://shiny.rstudio.com/articles/generating-reports.html 。

然后我尝试使用这个网站上显示的代码：

library(shiny)

server <- function(input, output) {
      output$report <- 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 <- file.path(tempdir(), "report.Rmd")
        file.copy("report.Rmd", tempReport, overwrite = TRUE)

    # Set up parameters to pass to Rmd document
        params <- 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())
        )})}

ui <- fluidPage(
     sliderInput("slider", "Slider", 1, 100, 50),
     downloadButton("report", "Generate report"))

shinyApp(ui = ui, server = server)

但是，我无法下载报告（Failed-Server问题）并收到错误：

Listening on http://127.0.0.1:3638
Warning in normalizePath(path, winslash = winslash, mustWork = mustWork) :
  path[1]="/tmp/Rtmp1BbjoR/test.Rmd": No such file or directory
Warning: Error in tools::file_path_as_absolute: file '/tmp/Rtmp1BbjoR/test.Rmd' does not exist
Stack trace (innermost first):
    58: tools::file_path_as_absolute
    57: dirname
    56: setwd
    55: rmarkdown::render
    54: download$func [example_code/report.R#23]
     5: <Anonymous>
     4: do.call
     3: print.shiny.appobj
     2: print
     1: print
Error : file '/tmp/Rtmp1BbjoR/test.Rmd' does not exist

我正在研究R服务器。 这个错误有什么建议吗？

提前致谢。

Answer 1

要在网站上重新创建示例，需要在工作目录中显示骨架.Rmd （名为report.Rmd ，最好创建为R脚本，以避免不可见的.txt ext。）文件。 此shell文件的内容在问题中提到的网页上给出。 所以步骤是：

1. 使用声明的网页创建一个文件report.Rmd 。 请确保它没有.txt扩展名。

2. 将其放在R会话的工作目录中。

3. 按原样运行代码。