R/glibrary.R

In drknexus/repsych: Package for reproducible psychological research

#' 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