Question

如果这太简单了，我很抱歉...我需要压缩一些生成的pdf以供下载使用。我尝试使用Zip函数，但失败了错误：

Warning: running command '"zip" -r9X "pdfs.zip" "plot_1.pdf" "plot_2.pdf" "plot_3.pdf" "plot_4.pdf" "plot_5.pdf" ' had status 127
Error opening file: 2
Error reading: 6

以下是我的代码，欢迎任何建议（基于shiny app : disable downloadbutton）：

UI.R

library(shiny)

shinyUI(fluidPage(
  singleton(tags$head(HTML(
'
  <script type="text/javascript">
    $(document).ready(function() {
      // disable download at startup. data_file is the id of the downloadButton
      $("#data_file").attr("disabled", "true").attr("onclick", "return false;");

      Shiny.addCustomMessageHandler("download_ready", function(message) {
        $("#data_file").removeAttr("disabled").removeAttr("onclick").html(
          "<i class=\\"fa fa-download\\"></i>Download " + message.fileSize + " ");
      });
    })
  </script>
'
))),
  tabsetPanel(
    tabPanel('Data download example',
      actionButton("start_proc", h5("Click to start processing data")),
      hr(),

      downloadButton("data_file"),
      helpText("Download will be available once the processing is completed.")
    )
  )
))

服务器UI.R

library(shiny)

get_a_pdf_plot <- function(my_i){
      pdf(paste("plot_", my_i, sep=""))
      plot(1:my_i*5, 1:my_i*5,
           xlim = c(1, my_i*5),
           ylim = c(1, my_i*5),
           main = paste("1:", my_i, sep = ""))
      dev.off()
}


shinyServer(function(input, output, session) {

  observe({
    if (input$start_proc > 0) {
      Sys.sleep(2)
      session$sendCustomMessage("download_ready", list(fileSize= "Ready"))
    }
  })

  output$data_file <- downloadHandler(
       filename = 'pdfs.zip',
       content = function(fname) {
        fs <- c()
        tmpdir <- tempdir()
        setwd(tempdir())
        print (tempdir())

        for (i in c(1,2,3,4,5)) {
          path <- paste("plot_", i, ".pdf", sep="")
          fs <- c(fs, path)
          get_a_pdf_plot(i)
        }
        print (fs)
        zip(zipfile="pdfs.zip", files=fs)
       }
  )
})

Answer 1

在get_a_pdf_plot中，您已经省略了.pdf

get_a_pdf_plot <- function(my_i){
  pdf(paste("plot_", my_i,".pdf", sep=""))
  plot(1:my_i*5, 1:my_i*5,
       xlim = c(1, my_i*5),
       ylim = c(1, my_i*5),
       main = paste("1:", my_i, sep = ""))
  dev.off()
}

在downloadHandler中，您需要提示下载类型：

 output$data_file <- downloadHandler(
    filename = 'pdfs.zip',
    content = function(fname) {
      fs <- c()
      tmpdir <- tempdir()
      setwd(tempdir())
      print (tempdir())

      for (i in c(1,2,3,4,5)) {
        path <- paste("plot_", i, ".pdf", sep="")
        fs <- c(fs, path)
        get_a_pdf_plot(i)
      }
      print (fs)
      zip(zipfile="pdfs.zip", files=fs)
    },
    contentType = "application/zip"
  )

Answer 2

这gist helped me setup the export。它在Mac上开箱即用。 Windows需要下载Rtools并指向Rtools中的zip（from this question）。我还没有遇到任何问题。

Sys.setenv(R_CMDZIP = 'C:/Rtools/bin/zip')

?zip文档提及＆＃34;在Windows上，默认依赖于zip程序（例如来自Rtools＆＃34;。如果你指向你最喜欢的zip程序的zip可执行文件我＆＃39; ;我相信它的工作方式类似（如果你不想下载Rtools）。

Shiny R Zip多个PDFS供下载

2 个答案: