download-packages.R

# This is saving a task I have every now and then to download a list of packages, and
# their dependencies, so that I can manually copy them somewhere.

# Date and R version should probably be parameterised

options("repos" = "https://mran.microsoft.com/snapshot/2018-01-01") # modern 
stopifnot(R.version$minor == "4.3")

#' Get package dependencies
#'
#' @param packs A string vector of package names
#'
#' @return A string vector with packs plus the names of any dependencies
getDependencies <- function(packs){
  dependencyNames <- unlist(
    tools::package_dependencies(packages = packs, db = available.packages(), 
                                which = c("Depends", "Imports"),
                                recursive = TRUE))
  packageNames <- union(packs, dependencyNames)
  packageNames
}

# Explicit dependencies that you need
pkgList <- c("ggplot2", "dplyr", "tidyr", "stringr", "roxygen2", "testthat", "devtools", "assertr")

# Calculate dependencies
packages <- getDependencies(pkgList)

pkgInfo <- download.packages(pkgs = packages, destdir = "Packages3.4/", type = "win.binary")
# Save just the package file names (basename() strips off the full paths leaving just the filename)

write.csv(file = "pkgFilenames.csv", basename(pkgInfo[, 2]), row.names = FALSE)


# Installing ----------------------------------------------------------------------------------

pkgsDir <- "D:/RSetup/Packages3.4" # wherever you put all those zip files

for (p in dir(pkgsDir, "*.zip")) {
  pth <- file.path(root, p)
  install.packages(pth, repos = NULL, type = "win.binary")
}