从Shiny下载

Question

我在闪亮的代码上使用以下代码。我希望能够下载表格和图表

Create data set from clicks in Shiny ggplot

代码本身可以正常工作，但是在弄清楚如何下载表格和绘图时遇到了麻烦。

library(shiny)
library(ggplot2)

ui <- pageWithSidebar(
    headerPanel("Example"),
    sidebarPanel(
        radioButtons("color", "Pick Color", c("Pink", "Green", "Blue")),
        selectInput("shape", "Select Shape:", c("Circle", "Triangle"))
    ),
    mainPanel(
        fluidRow(column(width = 6,
                        h4("Click plot to add points"),
                        actionButton("rem_point", "Remove Last Point"),
                        plotOutput("plot1", click = "plot_click")),
                 column(width = 6,
                        h4("Table of points on plot"),
                        tableOutput("table")))
    )
)

server = function(input, output){

    ## 1. set up reactive dataframe ##
    values <- reactiveValues()
    values$DT <- data.frame(x = numeric(),
                            y = numeric(),
                            color = factor(),
                            shape = factor())

    ## 2. Create a plot ##
    output$plot1 = renderPlot({
       ggplot(values$DT, aes(x = x, y = y)) +
            geom_point(aes(color = color,
                           shape = shape), size = 5) +
            lims(x = c(0, 100), y = c(0, 100)) +
            theme(legend.position = "bottom") +
            # include so that colors don't change as more color/shape chosen
            scale_color_discrete(drop = FALSE) +
            scale_shape_discrete(drop = FALSE)
    })

    ## 3. add new row to reactive dataframe upon clicking plot ##
    observeEvent(input$plot_click, {
        # each input is a factor so levels are consistent for plotting characteristics
        add_row <- data.frame(x = input$plot_click$x,
                              y = input$plot_click$y,
                              color = factor(input$color, levels = c("Pink", "Green", "Blue")),
                              shape = factor(input$shape, levels = c("Circle", "Triangle")))
        # add row to the data.frame
        values$DT <- rbind(values$DT, add_row)
    })

    ## 4. remove row on actionButton click ##
    observeEvent(input$rem_point, {
        rem_row <- values$DT[-nrow(values$DT), ]
        values$DT <- rem_row
    })

    ## 5. render a table of the growing dataframe ##
    output$table <- renderTable({
        values$DT
    })
}

shinyApp(ui, server)

rendertable中的values$DT是问题的症结所在，因为我没有闪亮示例中的datasetInput()。问题在于表格和绘图是动态的，需要像这样

进行更改

Download table generated independetly in renderTable output in R shiny

我不知道如何更改它。

Answer 1

下载用户生成的资料（图表）需要同时使用downloadButton和downloadHandler。 See here for help on understanding downloading.

针对您的情况，第一步是在用户界面中包含downloadButtons。

ui <- pageWithSidebar(
  headerPanel("Example"),
  sidebarPanel(
    radioButtons("color", "Pick Color", c("Pink", "Green", "Blue")),
    selectInput("shape", "Select Shape:", c("Circle", "Triangle")),
    downloadButton("dlPlot", "Download Current Plot"),
    downloadButton("dlTab", "Download Current Table")
  ),
  mainPanel(
    fluidRow(column(width = 6,
                    h4("Click plot to add points"),
                    actionButton("rem_point", "Remove Last Point"),
                    plotOutput("plot1", click = "plot_click")),
             column(width = 6,
                    h4("Table of points on plot"),
                    tableOutput("table")))
  )
)

下一步，在服务器中包含downloadHandler。我将此块放在服务器调用的末尾，没有其他更改：

  output$dlPlot <- downloadHandler(
    filename="Plot_Download.jpg",
    content=function(file){
      ggsave(file, device = "jpeg")
    }
  )

  output$dlTab <- downloadHandler(
    filename="Table_Download.csv",
    content=function(file){
      write.csv(x=values$DT, file=file)
    }
  )

我发现ggsave()和write.csv()是与downloadHandler一起使用的最简单的操作，但是还有其他方法，您可以在其他SO问题中找到。