R/accordion.R

In bsplus: Adds Functionality to the R Markdown + Shiny Bootstrap Framework

#' Accordion panel-group
#'
#' An accordion is a set of collapsible panels where, at most, one panel-body is visible.
#'
#' All of these functions return a `bsplus_accordion` object
#' (which is also an `htmltools::[tag][htmltools::tag]`, `<div/>`), so you can
#' compose an accordion by piping. There are three parts to this system:
#'
#' \enumerate{
#'   \item{A constructor function for the accordion, `bs_accordion()`}
#'   \item{A function to set options for subsequent panels, `bs_set_opts()`}
#'   \item{A function to append a panel to the group, `bs_append()`}
#' }
#'
#' The verb *append* is used to signify that you can append an arbitrary
#' number of panels to an accordion.
#'
#' For the constructor, `bs_accordion()`,
#' it is your responsibility to ensure that `id` is unique
#' among HTML elements in your page. If you have non-unique `id`'s, strange things may
#' happen to your page.
#'
#' @param id               character, unique id for accordion `<div/>`,
#'   also serves as root id for panels appended using `bs_append()`
#' @param tag              `htmltools::[tag][htmltools::tag]`,
#'   accordion `<div/>` to which to append a panel
#' @param title            character (HTML) or `htmltools::[tagList][htmltools::tagList]`,
#'   title for the panel heading
#' @param content          character (HTML) or `htmltools::[tagList][htmltools::tagList]`,
#'   content for the panel body
#' @param ...              other arguments (not used)
#' @param panel_type      character, one of the standard Bootstrap types
#'   `c("default", "primary", "success", "info", "warning", "danger")`
#' @param use_heading_link logical, indicates whether to make the entire panel heading
#'   clickable.
#'
#' @return `bsplus_accordion` object (`htmltools::[tag][htmltools::tag]`,
#'   `<div/>`)
#'
#' @examples
#' bs_accordion(id = "meet_the_beatles") %>%
#'   bs_set_opts(panel_type = "success", use_heading_link = TRUE) %>%
#'   bs_append(title = "John Lennon", content = "Rhythm guitar, vocals") %>%
#'   bs_set_opts(panel_type = "info") %>%
#'   bs_append(title = "Paul McCartney", content = "Bass guitar, vocals")
#'
#' @seealso <https://getbootstrap.com/docs/3.3/javascript/#collapse-example-accordion>
#' @export
#
bs_accordion <- function(id){

  div <- htmltools::tags$div(id = id, class = "panel-group", role = "tablist")
  div <- structure(div, class = c("bsplus_accordion", class(div)))
  div <- bs_set_aria(div, multiselectable = TRUE)
  div <- bs_set_opts(div, panel_type = "default", use_heading_link = FALSE)

  div
}