Or a massively overticked example from drknexus/repsych
on github, glibrary. There are almost certainly more efficient and better ways to to do this, but I programmed it a long while back and it basically works.
- It works even if a repo hasn't been selected by taking the default cloud option if available. If you are on an older version of R it will roll back and pick a mirror based on country code.
- It tries to load the library (this step could be made more efficient using some of the methods above)
- If it fails, it will try to install it
- If the install fails it will notify you which packages failed to install
- That is right, packages, multiple packages can be loaded/installed in a single pass along with their dependencies (at least usually, there may be a bug here).
e.g.: glibrary(xtable,sos,data.table)
but I don't think it will freak out if you call glibrary("xtable","sos","data.table")
instead. Pushes/pulls/forks welcome.
Code for the function:
#' Try to load a library, if that fails, install it, then load it.
#'
#' glibrary short for (get)library.
#' The primary aim of this function is to make loading packages more transparent. Given that we know we want to load a given package, actually fetching it is a formality. glibrary skims past this formality to install the requested package.
#'
#' @export
#' @param ... comma seperated package names
#' @param lib.loc See \code{\link{require}}
#' @param quietly See \code{\link{require}}
#' @param warn.conflicts See \code{\link{require}}
#' @param pickmirror If TRUE, glibrary allows the user to select the mirror, otherwise it auto-selects on the basis of the country code
#' @param countrycode This option is ignored and the first mirror with the substring "Cloud", e.g. the RStudio cloud, is selected. If no mirrors with that substring are identified, glibrary compares this value to results from getCRANmirrors() to select a mirror in the specified country.
#' @return logical; TRUE if glibrary was a success, an error if a package failed to load
#' @note keep.source was an arguement to require that was deprecated in R 2.15
#' @note This warning \code{Warning in install.packages: InternetOpenUrl failed: 'The operation timed out'} indicates that the randomly selected repository is not available. Check your internet connection. If your internet connection is fine, set pickmirror=TRUE and manually select an operational mirror.
#' @examples
#' #glibrary(lattice,MASS) #not run to prevent needless dependency
glibrary <- function(..., lib.loc = NULL, quietly = FALSE, warn.conflicts = TRUE, pickmirror = FALSE, countrycode = "us") {
warningHandle <- function(w) {
if (grepl("there is no package called",w$message,fixed=TRUE)) {
return(FALSE) #not-loadable
} else {
return(TRUE) #loadable
}
}
character.only <- TRUE #this value is locked to TRUE so that the function passes the character value to require and not the variable name thislib
librarynames <- unlist(lapply(as.list(substitute(.(...)))[-1],as.character))
#if package already loaded, remove it from librarynames before processing further
si.res <- sessionInfo()
cur.loaded <- c(si.res$basePkgs,names(si.res$otherPkgs)) #removed names(si.res$loadedOnly) because those are loaded, but not attached, so glibrary does need to handle them.
librarynames <- librarynames[librarynames %!in% cur.loaded]
success <- vector("logical", length(librarynames))
if (length(success)==0) {return(invisible(TRUE))} #everything already loaded, end.
alreadyInstalled <- installed.packages()[,"Package"]
needToInstall <- !librarynames %in% alreadyInstalled
if (any(needToInstall)) {
if (pickmirror) {chooseCRANmirror()}
if (getOption("repos")[["CRAN"]] == "@CRAN@") {
#Select the first "Cloud" if available
m <- getCRANmirrors(all = FALSE, local.only = FALSE)
URL <- m[grepl("Cloud",m$Name),"URL"][1] #get the first repos with "cloud" in the name
if (is.na(URL)) { #if we did not find the cloud,
#Fall back and use the previous method
message("\nIn repsych:glibrary: Now randomly selecting a CRAN mirror. You may reselect your CRAN mirror with chooseCRANmirror().\n")
#if there is no repository set pick a random one by country code
getCRANmirrors.res <- getCRANmirrors()
foundone <- FALSE #have we found a CRAN mirror yet?
#is it a valid country code?
if (!countrycode %in% getCRANmirrors.res$CountryCode) {
stop("In repsych::glibrary: Invalid countrycode argument")
}
ticker <- 0
while (!foundone) {
ticker <- ticker + 1
URL <- getCRANmirrors.res$URL[sample(grep(countrycode, getCRANmirrors.res$CountryCode), 1)]
host.list <- strsplit(URL, "/")
host.clean <- unlist(lapply(host.list, FUN = function(x) {return(x[3])}))
#make sure we can actually access the package list
if (nrow(available.packages(contrib.url(URL)))!=0) {foundone <- TRUE}
if (ticker > 5) {stop("In repsych::glibrary: Unable to access valid repository. Is the internet connection working?")}
} #end while
} #end else
repos <- getOption("repos")
repos["CRAN"] <- gsub("/$", "", URL[1L])
options(repos = repos)
} #done setting CRAN mirror
#installing packages
installResults <- sapply(librarynames[needToInstall],install.packages)
#checking for successful install
needToInstall <- !librarynames %in% installed.packages()[,"Package"]
if (any(needToInstall)) {
stop(paste("In repsych::glibrary: Could not download and/or install: ",paste(librarynames[needToInstall],collapse=", "),"... glibrary stopped.",sep=""))
} # done reporting any failure to install
} #done if any needed to install
#message("In repsych::glibrary: Attempting to load requested packages...\n")
#success <- tryCatch(
success <- sapply(librarynames,require, lib.loc = lib.loc, quietly = FALSE, warn.conflicts = warn.conflicts, character.only = TRUE)
#, warning=warningHandle) #end tryCatch
if(length(success) != length(librarynames)) {stop("A package failed to return a success in glibrary.")}
if (all(success)) {
#message("In repsych::glibrary: Success!")
return(invisible(TRUE))
} else {
stop(paste("\nIn repsych::glibrary, unable to load: ", paste(librarynames[!success]),
collapse = " "))
}
stop("A problem occured in glibrary") #shouldn't get this far down, all returns should be made.
}
NULL
require
(e.g. @SachaEpskamp's solution) is the way to go. Approaches that userownames(installed.packages())
are slow and are not always reliable (see Details of?find.package
and Note of?installed.packages
).require
ensures that packages are not only installed but are able to be used (i.e. dependencies are met, etc.). – jbaumspackageVersion("packageName")
– Kalanos