function for changing the Rstudio viewer settings across an R session

[barrettk]

The following function can change the default viewer settings between using the A) the Rstudio viewer, and B) opening a separate window. All HTML plots, Rmarkdown reports, shiny apps, etc. will be affected for the remainder of the R session:

Function

#' Set viewer option
#'
#' @param .view Method for viewing the R object
#'
#' @keywords internal
set_window_viewer <- function(.view = c("window", "viewer")) {
  .view <- match.arg(.view)

  view_call <- switch(.view,
                      viewer = rlang::quo(function(url, height) {
                        invisible(.Call("rs_viewer", url, height, PACKAGE = "(embedding)"))
                      }),
                      window = rlang::quo(function(url, height) {
                        invisible(.Call("rs_showPageViewer", url, title = "RStudio", self_contained = FALSE))
                      })
  )

  view_fn <- function(url, height = NULL) {
    if (!is.character(url) || length(url) != 1)
      stop("url must be a single element character vector.", call. = FALSE)

    if (identical(height, "maximize"))
      height <- -1

    if (!is.null(height) && (!is.numeric(height) || length(height) != 1))
      stop("height must be a single element numeric vector or 'maximize'.", call. = FALSE)

    # Evaluate the quoted expression in the environment of view_fn
    eval_tidy(view_call)(url, height)
  }

  options(viewer = view_fn)
}

Use

> set_window_viewer("window")
> result # opens as a new window
> set_window_viewer("viewer")
> result # opens in viewer