R/zzz.R

In CHNOSZ: Thermodynamic Calculations and Diagrams for Geochemistry

# CHNOSZ/zzz.R
# This has the .onAttach function for package startup message and data initialization

# The CHNOSZ environment is made here in open code 20190214
# https://stackoverflow.com/questions/41954302/where-to-create-package-environment-variables
CHNOSZ <- new.env()

.onLoad <- function(libname, pkgname) {

  # Add placeholder functions not present in earlier R versions 20190420
  # code inspired by backports::import
  if(getRversion() < "3.6.0") {
    pkg = getNamespace(pkgname)
    no.fun <- function(...) stop("this function is not available in this version of R")
    assign("hcl.pals", no.fun, envir = pkg)
    assign("hcl.colors", no.fun, envir = pkg)
  }

}

.onAttach <- function(libname,pkgname) {

  # Version figuring adapted from package mgcv
  pkghelp <- library(help = CHNOSZ)$info[[1]]
  # Things are different for older versions of R
  if(length(pkghelp) == 1) pkghelp <- library(help = CHNOSZ)$info[[2]]
  version <- pkghelp[pmatch("Version:", pkghelp)]
  um <- strsplit(version, " ")[[1]]
  version <- um[nchar(um)>0][2]
  date <- pkghelp[pmatch("Date:", pkghelp)]
  um <- strsplit(date, " ")[[1]]
  date <- um[nchar(um)>0][2]

  # Identify the program and version
  packageStartupMessage(paste("CHNOSZ version ", version, " (", date, ")", sep = ""))

  # Initialize the 'thermo' data object
  reset()

}