R/zzz.R

In ctrdata: Retrieve and Analyze Clinical Trials Data from Public Registers

### ctrdata package
### initialising

# create environment private to this package
# for caching field names, javascript functions;
# name of hidden environment: .ctrdataenv
# see also ctrCache in utils.R
.ctrdataenv <- new.env()

# check helper functions
.onAttach <- function(libname, pkgname) {

  # inform user
  packageStartupMessage(
    "\nInformation on this package and how to use it:\n",
    "https://cran.r-project.org/package=ctrdata\n\n",
    "Please respect the requirements and the copyrights of the\n",
    "clinical trial registers when using their information. Call\n",
    "ctrOpenSearchPagesInBrowser(copyright = TRUE) and visit\n\n",
    "https://www.clinicaltrialsregister.eu/disclaimer.html\n",
    "https://clinicaltrials.gov/about-site/terms-conditions#usage\n",
    "https://www.isrctn.com/page/faqs#using-the-isrctn\n",
    "https://euclinicaltrials.eu/about-this-website/\n",
    "\nPlease cite this package, see citation(\"ctrdata\").\n",
    "\n", utils::packageVersion("ctrdata")
  )

  # initialise
  initTranformers()

  # return
  return(invisible(NULL))

} # .onAttach

# helper
delCtrdataTempDir <- function(x) {delCtrdataTempDirHelper()}

delCtrdataTempDirHelper <- function() {

  # same as in function ctrTempDir()
  tempDir <- options()[["ctrdata.tempdir"]]
  if (is.null(tempDir)) return(invisible())
  keepDir <- file.path(tempDir, ".keepDir")
  if (!length(keepDir)) return(invisible())

  if (file.exists(keepDir)) {
    message('ctrdata: "verbose = TRUE", not deleting ',
            "temporary directory; re-use for ctrdata ",
            'by calling\noptions(ctrdata.tempdir = "',
            tempDir, '")')
  } else {
    unlink(tempDir, recursive = TRUE)
    message("ctrdata: deleted temporary directory.\r")
  }

}

reg.finalizer(
  e = globalenv(),
  f = delCtrdataTempDir,
  onexit = TRUE
)