i got stuck at some point while trying to use downloadHandler to download Plotly images. I just cannot figure out further how to get the image from temp directory...

Here is a sample code:

library(shiny)
library(plotly)
library(rsvg)
library(ggplot2)

d <- data.frame(X1=rnorm(50,mean=50,sd=10),X2=rnorm(50,mean=5,sd=1.5),Y=rnorm(50,mean=200,sd=25))

ui <-fluidPage(
 title = 'Download Plotly',
 sidebarLayout(

 sidebarPanel(
 helpText(),
 downloadButton('download'),
 tags$script('
 document.getElementById("download").onclick = function() 
 var plotly_svg = Plotly.Snapshot.toSVG(
 document.querySelectorAll(".plotly")[0]
 );

 Shiny.onInputChange("plotly_svg", plotly_svg);
 ;
 ')
 ),
 mainPanel(
 plotlyOutput('regPlot'),
 plotlyOutput('regPlot2')
 )
 )
)

server <- function(input, output, session) 

 output$regPlot <- renderPlotly(
 p <- plot_ly(d, x = d$X1, y = d$X2,mode = "markers")
 p
 )

 output$regPlot2 <- renderPlotly(
 p <- plot_ly(d, x = d$X1, y = d$X2,mode = "markers")
 p
 )

 observeEvent(input$plotly_svg, priority = 10, 
 png_gadget <- tempfile(fileext = ".png")
 png_gadget <- "out.png"
 print(png_gadget)
 rsvg_png(charToRaw(input$plotly_svg), png_gadget)
 )

 output$download <- downloadHandler(
 filename = function()
 paste(paste("test",Sys.Date(),sep=""), ".png",sep=""),
 content = function(file) 
 temp_dir <- tempdir()
 tempImage <- file.path(temp_dir, 'out.png')
 file.copy('out.png', tempImage, overwrite = TRUE)
 png(file, width = 1200, height = 800, units = "px", pointsize = 12, bg = "white", res = NA)
 dev.off()
 )


shinyApp(ui = ui, server = server)

Additionally i am not sure how can i choose which of the plotly images should be downloaded. Thanks for any tips and help!

Info:

--> I have tried using webshot, however if I zoom or filter in any way plot, unfortunatelly webshot does not mirror it

--> i am not using the available plotly panel for download, because it is not working using IE

The OP has edited his/her post to add a requirement:

--> I have tried using webshot, however if I zoom or filter in any way plot, unfortunatelly webshot does not mirror it

Below is a Javascript solution, which doesn't need additional libraries. I'm not fluent in Javascript and I'm not sure the method is the most direct one: I'm under the impression that this method creates a file object from a url and then it creates a url from the file object. I will try to minimize the code.

library(shiny)
library(plotly)

d <- data.frame(X1 = rnorm(50,mean=50,sd=10), 
 X2 = rnorm(50,mean=5,sd=1.5), 
 Y = rnorm(50,mean=200,sd=25))

ui <-fluidPage(
 title = 'Download Plotly',
 sidebarLayout(

 sidebarPanel(
 helpText(),
 actionButton('download', "Download")
 ),

 mainPanel(
 plotlyOutput('regPlot'),
 plotlyOutput('regPlot2'),
 tags$script('
 function download(url, filename, mimeType)
 return (fetch(url)
 .then(function(res)return res.arrayBuffer();)
 .then(function(buf)return new File([buf], filename, type:mimeType);)
 );
 
 document.getElementById("download").onclick = function() 
 var gd = document.getElementById("regPlot");
 Plotly.Snapshot.toImage(gd, format: "png").once("success", function(url) 
 download(url, "plot.png", "image/png")
 .then(function(file)
 var a = window.document.createElement("a");
 a.href = window.URL.createObjectURL(new Blob([file], type: "image/png"));
 a.download = "plot.png";
 document.body.appendChild(a);
 a.click();
 document.body.removeChild(a); 
 );
 );
 
 ')
 )
 )
)

server <- function(input, output, session) 

 regPlot <- reactive(
 plot_ly(d, x = d$X1, y = d$X2, mode = "markers")
 )
 output$regPlot <- renderPlotly(
 regPlot()
 )

 regPlot2 <- reactive(
 plot_ly(d, x = d$X1, y = d$X2, mode = "markers")
 )
 output$regPlot2 <- renderPlotly(
 regPlot2()
 )



shinyApp(ui = ui, server = server)

EDIT

I was right. There's a shorter and cleaner solution:

 tags$script('
 document.getElementById("download").onclick = function() 
 var gd = document.getElementById("regPlot");
 Plotly.Snapshot.toImage(gd, format: "png").once("success", function(url) 
 var a = window.document.createElement("a");
 a.href = url; 
 a.type = "image/png";
 a.download = "plot.png";
 document.body.appendChild(a);
 a.click();
 document.body.removeChild(a); 
 );
 
 ')

EDIT

To select the plot to download, you can do:

 sidebarLayout(

 sidebarPanel(
 helpText(),
 selectInput("selectplot", "Select plot to download", choices=list("plot1","plot2")),
 actionButton('download', "Download")
 ),

 mainPanel(
 plotlyOutput('regPlot'),
 plotlyOutput('regPlot2'),
 tags$script('
 document.getElementById("download").onclick = function() 
 var plot = $("#selectplot").val();
 if(plot == "plot1")
 var gd = document.getElementById("regPlot");
 else
 var gd = document.getElementById("regPlot2");
 
 Plotly.Snapshot.toImage(gd, format: "png").once("success", function(url) 
 var a = window.document.createElement("a");
 a.href = url; 
 a.type = "image/png";
 a.download = "plot.png";
 document.body.appendChild(a);
 a.click();
 document.body.removeChild(a); 
 );
 
 ')
 )
 )

1) Install the webshot package.

2) Install phantom.js:

library(webshot)
install_phantomjs()

See ?install_phantomjs for the details.

3) Now you can use the export function of the plotly package:

library(shiny)
library(plotly)

d <- data.frame(X1 = rnorm(50,mean=50,sd=10), 
 X2 = rnorm(50,mean=5,sd=1.5), 
 Y = rnorm(50,mean=200,sd=25))

ui <-fluidPage(
 title = 'Download Plotly',
 sidebarLayout(

 sidebarPanel(
 helpText(),
 downloadButton('download')
 ),

 mainPanel(
 plotlyOutput('regPlot'),
 plotlyOutput('regPlot2')
 )
 )
)

server <- function(input, output, session) 

 regPlot <- reactive(
 plot_ly(d, x = d$X1, y = d$X2, mode = "markers")
 )
 output$regPlot <- renderPlotly(
 regPlot()
 )

 regPlot2 <- reactive(
 plot_ly(d, x = d$X1, y = d$X2, mode = "markers")
 )
 output$regPlot2 <- renderPlotly(
 regPlot2()
 )

 output$download <- downloadHandler(
 filename = function()
 paste0(paste0("test", Sys.Date()), ".png")
 ,
 content = function(file) 
 export(regPlot(), file=file)
 )


shinyApp(ui = ui, server = server)

You can save to the svg format. See ?export for the explanations.