save html from data.frames to pdf using wkhtmltopdf or Markdown

Question

I have a df with a column htmltext containing html text that I would like to print (as a batch if possible) as single PDFs with doc_id as filename.

Can I do that directly within R?

I thought about something like

> system("wkhtmltopdf --javascript-delay 1 in.html out.pdf") 

how can I implement that in R? or is there another easy way to to so using markdown for example.

# df
doc_id <- c("doc1","doc2","doc3")
htmltext <- c("<b>good morning</b>","<b>This text is bold</b>","<b>good evening</b>")
df <- data.frame(doc_id,htmltext, stringsAsFactors = FALSE)

# save htmltext single pdfs with doc_id as filename
filenames = filenames = df$doc_id
...?

Answer 1

See if one of these is acceptable:

library(rmarkdown)
library(decapitated) # devtools::install_github("hrbrmstr/decapitated") # requires Chrome

data.frame(
  doc_id = c("doc1", "doc2", "doc3"),
  htmltext = c("<b>good morning</b>", "<b>This text is bold</b>", "<b>good evening</b>"), 
  stringsAsFactors = FALSE
) -> xdf

# hackish pandoc way
for(i in 1:nrow(xdf)) {
  message(sprintf("Processing %s", xdf$doc_id[i]))
  tf <- tempfile(fileext=".html")
  writeLines(xdf$htmltext[i], tf)
  pandoc_convert(
    input = tf, 
    to = "latex", 
    output = sprintf("%s.pdf", xdf$doc_id[i]),
    wd = getwd()
  )
  unlink(tf)
}

# using headless chrome
for(i in 1:nrow(xdf)) {
  message(sprintf("Processing %s", xdf$doc_id[i]))
  tf <- tempfile(fileext=".html")
  writeLines(xdf$htmltext[i], tf)
  chrome_dump_pdf(sprintf("file://%s", tf), path=sprintf("%s.pdf", xdf$doc[i]))
  unlink(tf)
}