R/DataViewer.R

In BrailleR: Improved Access for Blind Users

DataViewer =
    function(x, Update = FALSE, New = NULL, Filename = NULL) {
      # only for interactive sessions
      if (interactive()) {
        # check here that x is one of data.frame, matrix, or a vector.
        if (!is.data.frame(x) & !is.matrix(x) & !is.vector(x)) {
          .NotViewable() 
        }
        if (is.null(Filename)) {
          Filename = tempfile(pattern = "DV-", tmpdir = ".", fileext = ".csv")
        }
        write.csv(x, file = Filename)
        browseURL(Filename)

        readline( # waits for return value normally
            "Press <enter> once the viewing and editing is completed. \nOtherwise the temporary file will not be removed.")

        if (Update) {
          if (is.null(New)) {
            New = "New"
          }

          BringBack = read.csv(Filename, row.names = 1)
          # check for class of x
          if (is.matrix(x)) {
            BringBack = as.matrix(BringBack)
          }
          if (is.vector(x)) {
            BringBack = BringBack[, 1]
          }
          assign(New, BringBack, envir = parent.frame())
        }  # end Update

        file.remove(Filename)
      }  # end interactive
          else {
        .InteractiveOnly()
      }  # end not interactive
      invisible(NULL)
    }  # end function