Skip to content

Instantly share code, notes, and snippets.

@jbryer jbryer/package.R

Last active Feb 25, 2019
What would you like to do?
#' Simplified loading and installing of packages
#' This is a wrapper to \code{\link{require}} and \code{\link{install.packages}}.
#' Specifically, this will first try to load the package(s) and if not found
#' it will install then load the packages. Additionally, if the
#' \code{update=TRUE} parameter is specified it will check the currently
#' installed package version with what is available on CRAN (or mirror) and
#' install the newer version.
#' @param pkgs a character vector with the names of the packages to load.
#' @param install if TRUE (default), any packages not already installed will be.
#' @param update if TRUE, this function will install a newer version of the
#' package if available.
#' @param quiet if TRUE (default), package startup messages will be suppressed.
#' @param verbose if TRUE (default), diagnostic messages will be printed.
#' @param ... other parameters passed to \code{\link{require}},
#' \code{\link{install.packages}}, and
#' \code{\link{available.packages}}.
#' @return a data frame with four columns and rownames corresponding to the
#' packages to be loaded. The four columns are: loaded (logical
#' indicating whether the package was successfully loaded), installed
#' (logical indicating that the package was installed or updated),
#' loaded.version (the version string of the installed package), and
#' available.version (the version string of the package currently
#' available on CRAN). Note that this only reflects packages listed in
#' the \code{pkgs} parameter. Other packages may be loaded and/or
#' installed as necessary by \code{install.packages} and \code{require}.
#' If \code{verbose=FALSE} the data frame will be returned using
#' \code{\link{invisible}}.
#' @export
#' @example
#' \dontrun{
#' package(c('devtools','lattice','ggplot2','psych'))
#' }
package <- function(pkgs, install=TRUE, update=FALSE, quiet=TRUE, verbose=TRUE, ...) {
myrequire <- function(package, ...) {
result <- FALSE
if(quiet) {
suppressMessages(suppressWarnings(result <- require(package, ...)))
} else {
result <- suppressWarnings(require(package, ...))
mymessage <- function(msg) {
if(verbose) {
installedpkgs <- installed.packages()
availpkgs <- available.packages()[,c('Package','Version')]
if(nrow(availpkgs) == 0) {
warning(paste0('There appear to be no packages available from the ',
'repositories. Perhaps you are not connected to the ',
# It appears that hyphens (-) will be replaced with dots (.) in version
# numbers by the packageVersion function
availpkgs[,'Version'] <- gsub('-', '.', availpkgs[,'Version'])
results <- data.frame(loaded=rep(FALSE, length(pkgs)),
installed=rep(FALSE, length(pkgs)),
loaded.version=rep(as.character(NA), length(pkgs)),
available.version=rep(as.character(NA), length(pkgs)),
row.names(results) <- pkgs
for(i in pkgs) {
loadedPkgs <- search()
needInstall <- FALSE
if(i %in% row.names(installedpkgs)) {
v <- as.character(packageVersion(i))
if(i %in% row.names(availpkgs)) {
if(v != availpkgs[i,'Version']) {
if(!update) {
mymessage(paste0('A newer version of ', i,
' is available ', '(current=', v,
'; available=',
availpkgs[i,'Version'], ')'))
needInstall <- update
results[i,]$available.version <- availpkgs[i,'Version']
} else {
mymessage(paste0(i, ' is not available on the repositories.'))
} else {
if(i %in% row.names(availpkgs)) {
needInstall <- TRUE & install
results[i,]$available.version <- availpkgs[i,'Version']
} else {
warning(paste0(i, ' is not available on the repositories and ',
'is not installed locally'))
if(needInstall | !myrequire(i, character.only=TRUE)) {
install.packages(pkgs=i, quiet=quiet)
if(!myrequire(i, character.only=TRUE, ...)) {
warning(paste0('Error loading package: ', i))
} else {
results[i,]$installed <- TRUE
results[i,]$loaded <- TRUE
results[i,]$loaded.version <- as.character(packageVersion(i))
} else {
results[i,]$loaded <- TRUE
results[i,]$loaded.version <- as.character(packageVersion(i))
loadedPkgs2 <- search()
for(j in loadedPkgs2[!loadedPkgs2 %in% loadedPkgs]) {
try(detach(j, character.only=TRUE), silent=TRUE)
if(verbose) {
} else {

This comment has been minimized.

Copy link

drbardach commented Jul 19, 2016

Hey, I am really enjoying your solution to the, "check if package is installed and install it if necessary" problem. Thanks for making it! But I am not able to install using devtools::source_gist(), no matter which format of the examples on the source_gist {devtools} documentation page I use. I keep getting Error in r_files[[which]] : invalid subscript type 'closure'. I haven't been able to find anything on Google for such an error, so I thought I would at least let you know to see if maybe that error indicates something wrong with how it is set up on Gist? Unlikely, I know, but thought it was worth bringing to your attention. In the meantime, copy-pasting it as a function that I source before analysis is working for me. Thanks again!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.