R/install-version.R

In Mullefa/locallib: Project isolation for R

#' Install a particular version of a package into a local library
#'
#' @param pkg(string) Package name.
#' @param version(string) Package version. Default: latest version.
#' @param type(string) Type of package to download and install.
#'   Defaults to \code{"source"} if \code{getOption("pkgType")} is equal
#'   to \code{"source"}; else defaults to \code{"binary"}.
#'
#' @section Errors:
#' \itemize{
#'   \item{the \code{type} is not \code{source} or \code{binary}}
#'   \item{local library not activated}
#'   \item{latest version of package can't be found}
#'   \item{package can't be downloaded}
#' }
#'
#' @export
install_version <- function(pkg, version = NULL, type = NULL) {
  if (!is.activated()) {
    error("local library must be activated to use this function")
  }

  type <- type %||% default_pkg_type()

  if (type %notin% c("source", "binary")) {
    error("The type argument must be source or binary, not ", type, ".")
  }

  version <- version %||% local({
    # Throws an error if latest version can't be found.
    out <- latest_version(pkg, type)
    warn(
      "No version given for package ", pkg, " specified. ",
      "Installing the latest version ", bracket(out), "."
    )
    out
  })

  if (is.installed_locally(pkg, version)) {
    message(pkg, " ", bracket(version)," already installed locally")
  } else {
    # When installing a package which is not the latest version,
    # two scenarios are accounted for:
    #   1. the package will be in src/contrib/00Archive/<pkgname>/ (e.g. CRAN)
    #   2. the package will be in src/contrib/ (e.g. a drat repository)
    destfile <- download_pkg(pkg, version, type) %recover_with%
      download_pkg(pkg, version, type, use_archive = FALSE) %recover_with%
      error("Unable to download the package ", pkg, " ", bracket(version), ".")

    on.exit(unlink(destfile))

    # FIXME: if R_LIBS is set in .Renviron, this may not work for some reason?!
    install.packages(destfile, lib = local_lib(), repos = NULL)
  }
}


is.installed_locally <- function(pkg, version) {
  lib_pkg <- read_dcfs(local_lib())[[pkg]] %||% return(FALSE)
  # FIXME: what if version > lib_pkg$Version?
  version == lib_pkg$Version
}