R/utils.R

In tablerDash: 'Tabler' API for 'Shiny'

#' Assert that a tag has specified properties
#' @param tag A tag object.
#' @param type The type of a tag, like "div", "a", "span".
#' @param class An HTML class.
#' @param allowUI If TRUE (the default), allow dynamic outputs generated by
#'   \code{\link[shiny]{uiOutput}} or \code{\link[shiny]{htmlOutput}}. When a
#'   dynamic output is provided, \code{tagAssert} won't try to validate the the
#'   contents.
#' @keywords internal
tagAssert <- function(tag, type = NULL, class = NULL, allowUI = TRUE) {
  if (!inherits(tag, "shiny.tag")) {
    print(tag)
    stop("Expected an object with class 'shiny.tag'.")
  }

  # Skip dynamic output elements
  if (allowUI &&
      (hasCssClass(tag, "shiny-html-output") ||
       hasCssClass(tag, "shinydashboard-menu-output"))) {
    return()
  }

  if (!is.null(type) && tag$name != type) {
    stop("Expected tag to be of type ", type)
  }

  if (!is.null(class)) {
    if (is.null(tag$attribs$class)) {
      stop("Expected tag to have class '", class, "'")

    } else {
      tagClasses <- strsplit(tag$attribs$class, " ")[[1]]
      if (!(class %in% tagClasses)) {
        stop("Expected tag to have class '", class, "'")
      }
    }
  }
}


hasCssClass <- function(tag, class) {
  if (is.null(tag$attribs) || is.null(tag$attribs$class))
    return(FALSE)

  classes <- strsplit(tag$attribs$class, " +")[[1]]
  return(class %in% classes)
}


# Make sure a tab name is valid (there's no "." in it).
validateTabName <- function(name) {
  if (grepl(".", name, fixed = TRUE)) {
    stop("tabName must not have a '.' in it.")
  }
}