Saving from rCharts to image file

Question

I was wondering if there is a way to save a chart generated using rCharts to a file (as an image). In particular, I want to save a map generated using 'leaflet' to a file.

For example, a sample map can be generated using:

require(rCharts)
L1 <- Leaflet$new()
L1$set(width = 1600, height = 800)
L1$setView(c(0,0), 3)
L1 

This opens up a map in the browser. Now, I can right click on the map and select Save Image, but this saves only a single tile of the map. I want to save the whole map to file, and automate it using a bit of code, (rather than manually clicking and saving), because I need to run the process in a loop. Any suggestions?

Answer 1

I don't know about rCharts, but you might be able to use the Leaflet.print plugin to print to a static file.

Answer 2

This is years old, but I came across it searching for a solution for myself. I ended up creating one based on some other things I saw.

You can do this, but it has to be separated out into a few steps:

1. First, run your plot as you would in rCharts. Make sure the standalone option = TRUE
2. Next, save the plot as a stand alone html file
3. Next, use phantomjs and rasterize.js on your local system to render the html file you just created into an image file
4. Lastly, insert your image file

For the code below, assume your rCharts plot is already created as 'myplot'

tmpHtmlFile <- tempfile(fileext = '.html')
tmpPngFile <- tempfile(fileext = '.png')
myplot$save(tmpHtmlFile)
renderCommand <- sprintf('phantomjs ./reference/rasterize.js %s %s', tmpHtmlFile, tmpPngFile)
system(renderCommand)

Then use tmpPngFile to insert into your document