Input handlers: with getType

2. Define our custom handler when the package is loaded.

# on zzz.R

.onLoad <- function(...) {
  registerInputHandler(
    "OSUICode.textDate", function(data, ...) {
      if (is.null(data)) {
        NULL
      } else {
        res <- try(as.Date(unlist(data)), silent = TRUE)
        if ("try-error" %in% class(res)) {
          warning("Failed to parse dates!")
          data
        } else {
          res
        }
      }
  }, force = TRUE)
}