R/ilog.R

In myominnoo/mStatsLite: An lite version of mStats

#' @title Echo a copy of console to log file
#'
#' @description
#' \code{ilog()} echo a copy of console output to log file.
#'
#' @param logfile Name of desired log file in \code{.txt} format
#' @param append a logical value
#'
#' @details
#' \code{ilog} is a two-step function that allows you a record of your console.
#' A log is a file containing what you type and console output. If a name is not
#' specified, then \code{ilog} will use the name \code{<unnamed>.txt}.
#'
#' \code{ilog} opens a log file and \code{ilog.close} close the file.
#'
#' \strong{Warnings}:
#'
#' However, clearing objects from the workspace along with hidden objects
#' removes \code{ilog}'s \code{.logenv} environment, hence throwing an error
#' when it's attemptted to be closed. An error message
#' \code{Error in (function (cmd, res, s, vis)  : object '.logenv' not found}
#' will be thrown.
#'
#' In that case, console prompt is stuck at \code{log> }. If
#' this error occurs, use \code{ilogClearPrompt()} function to revert back to
#' normal.
#'
#' @keywords log, console ouput, save console, echo, copy
#'
#' @author
#'
#' For any feedback, please contact \code{Myo Minn Oo} via:
#'
#' Email: \email{dr.myominnoo@@gmail.com}
#'
#' Website: \url{https://myominnoo.github.io/}
#'
#' @examples
#' \dontrun{
#' ## my first log
#' ilog("../myFirstLog.tx")
#' str(infert)
#' str(iris)
#' ilog.close()
#'
#' # in case of error: ".logenv" not found
#' ilogClearPrompt()
#' }
#'
#' @export
ilog <- function(logfile = "LOG.txt", append = FALSE) {
  # create a global environment which can be accessed outside
  .logenv <<- new.env()
  # <-- create a connection file -->
  if(!append) {
    # <--- if logfile exists & replace is TRUE, remove logfile --->
    if(file.exists(logfile)) {
      unlink(logfile)
    }
  }
  # write log file
  con <- file(logfile, open ='a')
  .logenv$logfile <- logfile

  if(isOpen(con)) {
    .logenv$con.close <- FALSE
  } else {
    .logenv$con.close <- TRUE
    if(append) {
      open(con, open='a')
    } else {
      open(con, open='w')
    }
  }

  .logenv$con <- con
  .logenv$cmd <- TRUE
  .logenv$res <- TRUE
  .logenv$first <- TRUE

  .logenv$con.out <- textConnection(NULL, open='a')
  sink(.logenv$con.out, split=TRUE)

  .logenv$prompt <- unlist(options('prompt'))
  .logenv$continue <- unlist(options('continue'))

  options(prompt = paste('log', .logenv$prompt, sep = ''),
          continue = paste('log', .logenv$continue,sep = '') )

  # writing log info
  sink(logfile, append = TRUE, split = TRUE)
  printLines(width = 80)
  cat(paste0('\n      log: ', getwd(), "/", logfile,
             '\n  open on: ', Sys.time(),'\n'))
  if(append) {
    cat(paste0("     note: ", "appended\n"))
  } else {cat(paste0("     note: ", "replaced\n"))}
  printLines(width = 80)
  sink()

  addTaskCallback(ilogtxt, name = "ilogtxt")
  invisible(NULL)
}

#' @rdname  ilog
#' @export
ilog.close <- function() {
  removeTaskCallback(id = "ilogtxt")
  .logenv <- as.environment(.logenv)
  if(!.logenv$con.close) {
    close(.logenv$con)
  }
  options( prompt = .logenv$prompt,
           continue = .logenv$continue )
  if(.logenv$res) {
    sink()
    close(.logenv$con.out)
    # closeAllConnections()
  }
  # writing log info
  sink(.logenv$logfile, append = TRUE, split = TRUE)
  printLines(width = 80)
  cat(paste0('\n      log: ', getwd(), "/", .logenv$logfile,
             '\nclosed on: ',
             Sys.time(),'\n'))
  printLines(width = 80)
  sink()
  eval(rm(list= ".logenv", envir = sys.frame(-1)))
  invisible(NULL)
}

#' @rdname  ilog
#' @param cmd command line
#' @param res result
#' @param s others
#' @param vis others
#' @export
ilogtxt <- function(cmd, res, s, vis) {
  if(.logenv$first) {
    .logenv$first <- FALSE
    if( .logenv$res ) {
      sink()
      close(.logenv$con.out)
      .logenv$con.out <- textConnection(NULL, open='a')
      sink(.logenv$con.out, split=TRUE)
    }
  } else {
    if(.logenv$cmd){
      cmdline <- deparse(cmd)
      cmdline <- gsub('    ', paste("\n", .logenv$continue, sep =''),
                      cmdline)
      cmdline <- gsub('}', paste("\n", .logenv$continue,"}", sep =''),
                      cmdline)
      cat(.logenv$prompt, cmdline, "\n", sep = '',
          file=.logenv$con)
    }
    if(.logenv$res) {
      tmp <- textConnectionValue(.logenv$con.out)
      if(length(tmp)) {
        cat(tmp, sep='\n', file = .logenv$con)
        sink()
        close(.logenv$con.out)
        .logenv$con.out <- textConnection(NULL, open='a')
        sink(.logenv$con.out, split=TRUE)
      }
    }
  }
  TRUE
}


#' @rdname  ilog
#' @export
ilogClearPrompt <- function()
{
  options(prompt = "> ", continue = "+ ")
}