loop merging all pdf files from subfolders

Question

I am trying create a loop to merge all pdfs from subfolders and create a unique pdf for each subfolder with the name of the subfolder's name.

As an Example: I have the "23201018", inside of which I have subfolders and other documents, which are irrelevant

• "T34709"
• "T8257"
• etc

inside each subfolder there are several pdf's I would like to merge and give, the resultig merged pdf,the name of the subfolder.

I managed to run this for one subfolder at a time

wd<-setwd(WDPATH)
list.files(paste0(wd,"/23201018"))# Folder with subfolders inside
#  "23201018.XLSX" "T34709" "T26045" "T85625"
list.files(paste0(wd,"/23201018/T34709")) # I tried for one subfolder at a time


# CREATES A JOIN PDF WITH ALL THE DOCUMENTS IN THE FOLDER
staple_pdf(
  input_directory = paste0(wd,"/23201018/T34709"),
  input_files = NULL,
  output_filepath = paste0(wd,"/23201018/T34709/",basename(paste0(wd,"/23201018/T34709")),".pdf"),
  overwrite = FALSE
)

how can I make this inside a loop?

Answer 1

Here is an example that assumes that your current working directory contains a folder called “23201018”. Within that folder are subfolders “one” and “two” which contain pdf files. There is another folder “no_pdf”, which has no pdf files.

1. Gather all folders that have pdf files in them.
2. Create a vector with the file paths for the pdf files.
3. Use mapply() to feed it all into the staplr::staple_pdf() function.

library(staplr)

list.dirs("23201018/")
#> [1] "23201018/"        "23201018//no_pdf" "23201018//one"    "23201018//two"

folder_names <- 
  list.files("23201018/", recursive = TRUE, pattern = "\\.pdf",
             full.names = TRUE) |> 
  dirname() |> 
  unique()

pdf_names <- 
  paste0(folder_names, ".pdf") 

pdf_paths <- 
  file.path("23201018", pdf_names)

mapply(\(x, y) staple_pdf(input_directory = x,
                          output_filepath = y), 
       folder_names,
       pdf_names)
#> 23201018//one 23201018//two 
#>          TRUE          TRUE