如何使用R Shiny downloadHandler下载ggplotly图？

Question

I'm making a Shiny app in R. I use plotly to make my ggplots interactive, thus I have lots of ggplotly plots in the app. I would like to be able to download each one through a button on the interface.

My download button works for normal ggplot objects but not for ggplotly objects. A simple reproducible example would be:

library(shiny)
library(ggplot2)
library(processx) # for orca()
library(plotly)

ui <- fluidPage(
  mainPanel(plotlyOutput("plot1"), downloadButton('download1', 'Download Graph'))
  )

server <- function(input,output){
  make_plot1 <- function(){
    p1 = ggplot(cars, aes(x = speed, y = dist)) + geom_point()
    return(ggplotly(p1))}

  output$plot1 <- renderPlotly({ make_plot1() }) 

  output$download1 <- downloadHandler(
    filename = function() {'plot1.png'},
    content = function(file) {
      # try 1
      png(file)
      print(make_plot1())

      # try 2
      #plotly_IMAGE(make_plot1(), format = "png", out_file = file)

      # try 3
      #orca(make_plot1(), file)

      #try 4
      #export(make_plot1(), file = file)

      dev.off()
      })
  }

shinyApp(ui, server)

Some things I've tried are commented out in that code.

Try 1 is based on how I would normally handle plot objects in a shiny app

Try 2 is based on this question and this post

Try 3 is based on some plotly documentation

Try 4 is based on this question

All of these attempts either download a blank .png (try 1) or simply fail to download anything (tries 2-4). I suspect I'm not quite using the download Handler correctly. Anybody have suggestions for getting this working?

EDIT: For this case I want .png files, but there are some good answers on this thread for downloading interactive .html files.

Answer 1

Do you need to accomplish this with a download button for some reason? If not, plotly has its own button in the modebar that downloads to a PNG.

Dashboard taken from https://plot.ly/r/dashboard/ .

From the plotly support forum ( https://community.plot.ly/t/remove-options-from-the-hover-toolbar/130/3 ), you can use config() to remove the other components.

make_plot1 <- function() {
  p1 = ggplot(cars, aes(x = speed, y = dist)) + geom_point()
  p1 = ggplotly(p1) %>%
    config(
      modeBarButtonsToRemove = list(
        "zoom2d",
        "pan2d",
        "zoomIn2d",
        "zoomOut2d",
        "autoScale2d",
        "resetScale2d",
        "hoverClosestCartesian",
        "hoverCompareCartesian",
        "sendDataToCloud",
        "toggleHover",
        "resetViews",
        "toggleSpikelines",
        "resetViewMapbox"
      ),
      displaylogo = FALSE
    )
  return(p1)
}

You can also move the modebar so that it doesn't cover the plot, using CSS.

.modebar {
    top: -30px !important;
}

Answer 2

Another way would be to use htmlwidgets to save the file as an interactive html, in case that is preferable to a png.

To turn this html into a static graphic, a further workaround - if you for some reason do not want to use plotly's printing function at all - would be to save a png with webshot (which requires phantomjs). See code below.

library("shiny")
library("ggplot2")
library("data.table")
library("plotly")
library("htmlwidgets")
library("webshot")


shinyApp(

  ui = fluidPage(

    mainPanel(plotlyOutput("plot1"),
              downloadButton('download1', 'Download Graph'))
  ),

  server = function(input, output) {

    inputPlot1 <- reactive({
      p1 = ggplot(cars, aes(x = speed, y = dist)) + geom_point()
      ggplotly(p1)
    })

    output$plot1 <- renderPlotly({
      print(inputPlot1())
    })

    output$download1 <- downloadHandler(
      filename = function() {'plot1.html'},
      content = function(file) {

      htmlwidgets::saveWidget(as_widget(inputPlot1()), file)

        # Alternative using webshot with phantomjs
        # saveWidget(as_widget(inputPlot1()), "temp.html", selfcontained = FALSE)
        # webshot(url = "temp.html", file)

      }
    )

  }

) # closes shinyApp

Answer 3

Following your comment to Wil's answer, you can remove the undesired buttons in the modebar as follows:

library(plotly)

x <- c(1:15)
y <- c(1:15)
xy <- as.data.frame(cbind(x,y))
example <- ggplot(data = xy,aes(x = x,y = y)) + geom_line()

ggplotly(example) %>% 
  config(displaylogo = FALSE,
         collaborate = FALSE,
         modeBarButtonsToRemove = list(
           'sendDataToCloud',
           'autoScale2d',
           'resetScale2d',
           'hoverClosestCartesian',
           'hoverCompareCartesian',
           'zoom2d', 
           'pan2d',
           'select2d',
           'lasso2d',
           'zoomIn2d', 
           'zoomOut2d',
           'toggleSpikelines'
         )
  )

References:

• https://stackoverflow.com/a/39985051/1100107

• http://www.somesolvedproblems.com/2018/10/how-to-customize-plotlys-modebar.html

• ?plotly::config

Answer 4

如果您希望下载具有交互功能的ggplotly图，请尝试以下方法 。