Is it possible to programmatically export a list of networks one by one to PNG in the R package visNetwork?

I tried sample codes for visExport() and is able to add a "Export as PNG" button to a Shiny webpage. But this would need user interaction to press the button to export the network to a PNG image file.

I have over hundred of networks and would like to export them each to a PNG file. And some of these would need regular updating. So it would be logistically nice to be able to export all them to PNG files without a user pressing the "Export as PNG" button for each of the network.

So is it possible to programmatically export a list of networks one by one to PNG? This would be just like for visSave() to export the HTML for each network one by one.

Solution

In reference to other post, here is working code making use of the webshot package.

library(visNetwork)
library(tidyverse)
library(webshot)

# create network data
nodes = data.frame(id = numeric(),label=character(),set = numeric(),stringsAsFactors = F)
edges = data.frame(from = numeric(),to = numeric(),set = numeric(),stringsAsFactors = F)
for (i in 1:10){
  tempNodes <- data.frame(id = 1:15, label = paste("Label", 1:15), set = i)
  tempEdges <- data.frame(from = trunc(runif(15)*(15-1))+1,
                          to = trunc(runif(15)*(15-1))+1, set = i)
  nodes = rbind(nodes,tempNodes)
  edges = rbind(edges,tempEdges)
}

# loop through each set to export to PNG
for (i in 1:max(nodes$set)){
  subNodes = nodes[nodes$set==i,]
  subEdges = edges[edges$set==i,]
  network = visNetwork(subNodes, subEdges, width="100vw",height = "100vh") %>% 
    visLayout(randomSeed=1,improvedLayout=TRUE) %>% 
    visGroups(groupname = "actorImported",shape="circle") %>%  
    visEdges(smooth=FALSE) %>% 
    visPhysics(solver = "barnesHut") 
  fname = paste0("network",sprintf("%03d",i),".html")
  visSave(network,fname)
  webshot(fname,delay=0.5,zoom=2,file=paste0("network",sprintf("%03d",i),".png"),
          vwidth=900,vheight=900)
}