R/twsClock.R

In twsInstrument: Improves ease of use of IBrokers and FinancialInstrument

#' A clock utility to display the TWS server time...
#' 
#' A clock utility to display the TWS server time
#' 
#' adapted from the code in the links in references
#' 
#' @param format format
#' @param refresh refresh rate
#' @param verbose be verbose about what clientId you are connected with?
#' @return live updating current time as reported by \code{\link[IBrokers]{reqCurrentTime}}.
#' Press escape to exit clock utility.
#' @references
#' \url{http://stackoverflow.com/questions/5953718/overwrite-current-output-in-the-r-console}
#' 
#' \url{http://4dpiecharts.com/2011/05/11/a-clock-utility-via-console-hackery/}
#' 
#' \url{http://www.asciitable.com/}
#' @examples
#' \dontrun{
#' twsClock()
#' twsClock("%A %d %B %Y %I:%M:%OS3 %p", 1e-3)
#' }
#' @export
twsClock <- function(format = "%H:%M:%S", refresh = 1, verbose=TRUE)
{
    tws <- ConnectIB(c(140:144, 150))
    tryCatch({
        if (isConnected(tws) && verbose) 
            cat(paste("Connected with clientId", tws$clientId, '\n'))
        if (tws$clientId == 150) 
            warning("IB TWS should be restarted.")    
        repeat
        {
            cat("\r", format(reqCurrentTime(tws), format), sep = "")
            flush.console()
            Sys.sleep(refresh)
        }
    }, finally = {
        twsDisconnect(tws)
    })
}