r - 尝试在 Shiny App 中使用 RMarkdown 下载 PDF

Question

我正在尝试从 Shiny App 中生成 PDF 格式的报告。我有两个问题：

1. 报告没有以 PDF 格式下载，仅以 HTML 格式下载。我如何下载它的PDF？
2. 报告未显示渲染的内容（在本例中为 ggplotly 图像），仅显示文本。如何使该 PDF 包含 Shiny App 中显示的图像？

我究竟做错了什么？有任何想法吗？

library(ggplot2)
library(plotly)
library(gapminder)
library(shiny)
library(shinydashboard)
library(rmarkdown)

bodyplotly <- dashboardBody(
  fluidRow(
    column(12,
           box(width=10,
               title = "ggplotly", 
               plotlyOutput("selected_plot"),
               box(
                 width = 2, height=250,
                 sliderInput("year", label=("Choose year"),
                             min = 1950, max = 2000, value = 1977),
                 downloadButton("report", "Generate report")
           )))))  
  
ui <- navbarPage("Test",tabPanel("plotly",
                          bodyplotly))

server <- function(input, output,session) {
  
  output$selected_plot <- renderPlotly({
    
    p <- gapminder %>%
      filter(year==input$year) %>%
      ggplot( aes(gdpPercap, lifeExp, size = pop, color=continent)) +
      geom_point() +
      theme_bw()
    
    ggplotly(p)
    
    
  })
  
  output$downloadreport <- downloadHandler(
    # For PDF output, change this to "report.pdf"
    filename = "report.html",
    content = function(file) {
      # Copy the report file to a temporary directory before processing it, in
      # case we don't have write permissions to the current working dir (which
      # can happen when deployed).
      tempReport <- file.path(tempdir(), "report.Rmd")
      file.copy("report.Rmd", tempReport, overwrite = TRUE)
      library(rmarkdown)
      # Set up parameters to pass to Rmd document
      params <- list(input$year)
      # 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, pdf_document(),
                        #output_options=self_contained,
                        #params = params,
                        envir = new.env(parent = globalenv())
      )
    
    }
  )
  
  }
  
  shinyApp(ui = ui, server = server)

标签： rshinyr-markdownshinydashboardggplotly