--- a
+++ b/R/requireBrainarray.R
@@ -0,0 +1,61 @@
+#' Installs brainarray CDF and probe information packages
+#'
+#' This package downloads, installs, and/or loads the brainarray CDF and probe
+#' enviroments from the Brainarray website.
+#'
+#' @param array_type A character of length 1 giving the giving the name of the'
+#'   array. (Preferably as returned by \code{affyio::read.celfile.header})
+#' @param custom_cdf A charcter giving the annotation type.
+#' @param version A character of length 1 giving the version to download.
+#' @return Invisibly returns a list of the locations of the saved files.
+#' @author
+#'   Steffen Falgreen,
+#'   Anders Ellern Bilgrau
+#' @seealso \code{\link{tempdir}}, \code{\link{install.packages}}
+#' @references
+#'   See \url{http://brainarray.mbni.med.umich.edu}.
+#' @examples
+#' tmp.path <- requireBrainarray("hgu133a", custom_cdf = "enst",
+#'                               version = "18.0.0")
+#' print(tmp.path)
+#' tmp.path2 <- requireBrainarray("hgu133a", custom_cdf = "enst")
+#' print(tmp.path2)
+#' @import AnnotationDbi
+#' @export
+requireBrainarray <- function(array_type,
+                              custom_cdf = "enst",
+                              version = getLatestVersion()) {
+  output <- list()
+  brain_dat <- output[["brain_dat"]] <-
+    readBrainarrayTable(custom_cdf = custom_cdf, version = version)
+
+  base_url <- attributes(brain_dat)$base_url
+  if (getSubversion(version) >= 19) {
+    base_url <- paste0("http://mbni.org/customcdf/", version, "/",
+                       tolower(custom_cdf))
+  }
+
+  pkgs <- getBrainarrayPackages(brain_dat, array_type = array_type)
+
+  for (pkg in pkgs) {
+    loaded <- suppressWarnings(require(pkg, character.only = TRUE))
+    if (!loaded || packageVersion(pkg) != version) {
+      if (loaded) {
+         message("Installed package version is not ", version,
+                 ". Overwriting installed package.", sep = "")
+      }
+      file.pkg <- paste0(pkg, "_", version, ".tar.gz")
+
+      # Construct url and download package
+      pkg_url <- file.path(paste0(base_url, ".download"), file.pkg)
+      pkg_dest <- output[[pkg]] <- file.path(tempdir(), file.pkg)
+      download.file(url = pkg_url, destfile = pkg_dest)
+
+      # Install and load package
+      install.packages(pkgs = pkg_dest, repos = NULL, type = "source")
+      require(pkg, character.only = TRUE)
+    }
+  }
+
+  return(invisible(output))
+}