R/check.update.R

In MarkusN-fr/ordijuice2017: Unconstrained ordinations of vegetation data in JUICE program

#' Check for a new version of ordijuice.
#'
#' \code{check.update} checks for a new version of ordijuice on the servers of
#' Masaryk University Brno. This function might become obsolete if the
#' ordijuice package can be successfully hosted on the CRAN repositories.
#'
#' @seealso \code{\link{check.install}}

#--------------------------------------------


check.update <-

  function ()

  {

    new.available <- FALSE

    last.checking <- NULL

    try(load ('updtchck.r'), silent = T) #run an expression that might fail; silent -> should the error messages be suppressed ?

    if (is.null (last.checking))

    {

      checking <- NULL

      try(checking <- old.packages ('../library', contriburl = 'http://sci.muni.cz/botany/zeleny/R/windows/contrib/R-2.8.1/'), silent = T)
      #indicates packages which have a (suitable) later version on the repositories

      if (!is.null(checking)) if (checking[,5] > checking[,3]) new.available <- TRUE

      last.checking <- as.numeric(format (Sys.time(), "%y%m%d%H%M%OS1"))

      save (last.checking, file = 'updtchck.r')

    } else

    {

      if (as.numeric(format(Sys.time(), "%y%m%d%H%M%OS1"))-last.checking > 1000000)

      {

        checking <- NULL

        try(checking <- old.packages ('../library', contriburl = 'http://sci.muni.cz/botany/zeleny/R/windows/contrib/R-2.8.1/'))

        if (!is.null(checking)) if (checking[,5] > checking[,3]) new.available <- TRUE

        last.checking <- as.numeric(format (Sys.time(), "%y%m%d%H%M%OS1"))

        save (last.checking, file = 'updtchck.r')

      }

    }

    if (new.available)

    {

      answ <- winDialog.m ('yesnocancel', 'New update of ORDIJUICE is available online. \nDo you want to update now?')

      if (answ == 'YES') install.libraries ('ordijuice')

    }

  }