R/Viewer.R

#' @importFrom utils browseURL
NULL

#' Display an `rtable` object in the Viewer pane in RStudio or in a browser
#'
#' The table will be displayed using bootstrap styling.
#'
#' @param x (`rtable` or `shiny.tag`)\cr an object of class `rtable` or `shiny.tag` (defined in `htmltools` package).
#' @param y (`rtable` or `shiny.tag`)\cr optional second argument of same type as `x`.
#' @param ... arguments passed to [as_html()].
#'
#' @return Not meaningful. Called for the side effect of opening a browser or viewer pane.
#'
#' @examples
#' if (interactive()) {
#'   sl5 <- factor(iris$Sepal.Length > 5,
#'     levels = c(TRUE, FALSE),
#'     labels = c("S.L > 5", "S.L <= 5")
#'   )
#'
#'   df <- cbind(iris, sl5 = sl5)
#'
#'   lyt <- basic_table() %>%
#'     split_cols_by("sl5") %>%
#'     analyze("Sepal.Length")
#'
#'   tbl <- build_table(lyt, df)
#'
#'   Viewer(tbl)
#'   Viewer(tbl, tbl)
#'
#'
#'   tbl2 <- htmltools::tags$div(
#'     class = "table-responsive",
#'     as_html(tbl, class_table = "table")
#'   )
#'
#'   Viewer(tbl, tbl2)
#' }
#' @export
Viewer <- function(x, y = NULL, ...) {
  check_convert <- function(x, name, accept_NULL = FALSE) {
    if (accept_NULL && is.null(x)) {
      NULL
    } else if (is(x, "shiny.tag")) {
      x
    } else if (is(x, "VTableTree")) {
      as_html(x, ...)
    } else {
      stop("object of class rtable or shiny tag excepted for ", name)
    }
  }

  x_tag <- check_convert(x, "x", FALSE)
  y_tag <- check_convert(y, "y", TRUE)

  html_output <- if (is.null(y)) {
    x_tag
  } else {
    tags$div(class = "container-fluid", htmltools::tags$div(
      class = "row",
      tags$div(class = "col-xs-6", x_tag),
      tags$div(class = "col-xs-6", y_tag)
    ))
  }

  sandbox_folder <- file.path(tempdir(), "rtable")

  if (!dir.exists(sandbox_folder)) {
    dir.create(sandbox_folder, recursive = TRUE)
    pbs <- file.path(path.package(package = "rtables"), "bootstrap/")
    file.copy(list.files(pbs, full.names = TRUE, recursive = FALSE), sandbox_folder, recursive = TRUE)
    # list.files(sandbox_folder)
  }

  # get html name
  n_try <- 10000
  for (i in seq_len(n_try)) {
    htmlFile <- file.path(sandbox_folder, paste0("table", i, ".html"))

    if (!file.exists(htmlFile)) {
      break
    } else if (i == n_try) {
      stop("too many html rtables created, restart your session")
    }
  }

  html_bs <- tags$html(
    lang = "en",
    tags$head(
      tags$meta(charset = "utf-8"),
      tags$meta("http-equiv" = "X-UA-Compatible", content = "IE=edge"),
      tags$meta(
        name = "viewport",
        content = "width=device-width, initial-scale=1"
      ),
      tags$title("rtable"),
      tags$link(
        href = "css/bootstrap.min.css",
        rel = "stylesheet"
      )
    ),
    tags$body(
      html_output
    )
  )

  cat(
    paste("<!DOCTYPE html>\n", htmltools::doRenderTags(html_bs)),
    file = htmlFile, append = FALSE
  )

  viewer <- getOption("viewer")

  if (!is.null(viewer)) {
    viewer(htmlFile)
  } else {
    browseURL(htmlFile)
  }
}