R/revealjs_presentation.R - IDS-Mannheim/revealjs - Gitiles

 #' Convert to a reveal.js presentation
 #'
 #' Format for converting from R Markdown to a reveal.js presentation.
 #'
 #' In reveal.js presentations you can use level 1 or level 2 headers for slides.
 #' If you use a mix of level 1 and level 2 headers then a two-dimensional layout
 #' will be produced, with level 1 headers building horizontally and level 2
 #' headers building vertically.
 #'
 #' For additional documentation on using revealjs presentations see
 #' <https://github.com/rstudio/revealjs>
 #'
 #' # About plugins
 #'
 #' ## Built-in plugins with reveal.js
 #'
 #' ### Zoom
 #'
 #' When activated, ALT + Click can be used to zoom on a slide.
 #'
 #' ### Notes
 #'
 #' Show a [speaker view](https://revealjs.com/speaker-view/) in a separated
 #' window. This speaker view contains a timer, current slide, next slide, and
 #' speaker notes. It also duplicate the window to have presentation mode
 #' synchronized with main presentation.
 #'
 #' Use
 #' ```markdown
 #' ::: notes
 #' Content of speaker notes
 #' :::
 #' ```
 #' to create notes only viewable in presentation mode.
 #'
 #' ### Search
 #'
 #' When opt-in, it is possible to show a search box when pressing `CTRL + SHIFT +
 #' F`. It will seach in the whole presentation, and highlight matched words. The
 #' matches will also be highlighted in overview mode (pressing ESC to see all
 #' slides in one scrollable view)
 #'
 #' ## Menu
 #'
 #' A slideout menu plugin for Reveal.js to quickly jump to any slide by title.
 #'
 #' Version `r version <- readLines(revealjs_lib_path("plugin", "menu", "VERSION"))` is
 #' currently used and documentation for configurations can be found at
 #' [denehyg/reveal.js-menu](https://github.com/denehyg/reveal.js-menu/blob/`r version`/README.md)
 #'
 #' ### Known limitations
 #'
 #' Some configurations cannot be modified in the current template:
 #'
 #' * `loadIcons: false`  the fontawesome icons are loaded by \pkg{rmarkdown}
 #' when this plugin is used
 #' * `custom: false`
 #' * `themes: false`
 #' * `transitions: false`

 #' ## Chalkboard
 #'
 #' A plugin adding a chalkboard and slide annotation
 #'
 #' Version `r version <- readLines(revealjs_lib_path("plugin", "chalkboard", "VERSION"))` is
 #' currently used and documentation for configurations can be found at
 #' [rajgoel/reveal.js-plugins](https://github.com/rajgoel/reveal.js-plugins/tree/`r version`/4.1.5/chalkboard)
 #'
 #' By default, chalkboard and annotations modes will be accessible using keyboard
 #' shortcuts, respectively, pressing B, or pressing C.
 #' In addition, buttons on the bottom left can be added by using the following
 #'
 #' ```yaml
 #' reveal_plugins:
 #'   - chalkboard
 #' reveal_options:
 #'   chalkboard:
 #'     toggleNotesButton: true
 #'     toggleChalkboardButton: true
 #' ```
 #' @inheritParams rmarkdown::beamer_presentation
 #' @inheritParams rmarkdown::pdf_document
 #' @inheritParams rmarkdown::html_document
 #'
 #' @param center `TRUE` to vertically center content on slides
 #' @param slide_level Level of heading to denote individual slides. If
 #'   `slide_level` is 2 (the default), a two-dimensional layout will be
 #'   produced, with level 1 headers building horizontally and level 2 headers
 #'   building vertically. It is not recommended that you use deeper nesting of
 #'   section levels with reveal.js.
 #' @param theme Visual theme (`r knitr::combine_words(setdiff(revealjs_themes(), "default"), before = '"', and = " or ")`)
 #' @param transition Slide transition (
 #' `r (trans <- knitr::combine_words(setdiff(revealjs_transitions(), "default"), before = '"', and = " or "))`
 #' )
 #' @param background_transition Slide background-transition (
 #' `r trans`
 #' )
 #' @param reveal_options Additional options to specify for reveal.js (see
 #'   <https://revealjs.com/config/> for details). Options for plugins can also
 #'   be passed, using plugin name as first level key (e.g `list(slideNumber =
 #'   FALSE, menu = list(number = TRUE))`).
 #' @param reveal_plugins Reveal plugins to include. Available plugins include
 #'   "notes", "search", "zoom", "chalkboard", and "menu". Note that
 #'   `self_contained` must be set to `FALSE` in order to use Reveal
 #'   plugins.
 #' @param template Pandoc template to use for rendering. Pass "default" to use
 #'   the rmarkdown package default template; pass `NULL` to use pandoc's
 #'   built-in template; pass a path to use a custom template that you've
 #'   created. Note that if you don't use the "default" template then some
 #'   features of `revealjs_presentation` won't be available (see the
 #'   Templates section below for more details).
 #' @param extra_dependencies Additional function arguments to pass to the base R
 #'   Markdown HTML output formatter [rmarkdown::html_document_base()].
 #' @param ... Ignored
 #'
 #' @return R Markdown output format to pass to [rmarkdown::render()]
 #'
 #' @examples
 #' \dontrun{
 #'
 #' library(rmarkdown)
 #' library(revealjs)
 #'
 #' # simple invocation
 #' render("pres.Rmd", revealjs_presentation())
 #'
 #' # specify an option for incremental rendering
 #' render("pres.Rmd", revealjs_presentation(incremental = TRUE))
 #' }
 #'
 #' @export
 revealjs_presentation <- function(incremental = FALSE,
                                   center = FALSE,
                                   slide_level = 2,
                                   toc = FALSE,
                                   toc_depth = 3,
                                   fig_width = 8,
                                   fig_height = 6,
                                   fig_retina = if (!fig_caption) 2,
                                   fig_caption = FALSE,
                                   self_contained = TRUE,
                                   theme = "simple",
                                   transition = "convex",
                                   background_transition = "fade",
                                   reveal_options = NULL,
                                   reveal_plugins = NULL,
                                   highlight = "default",
                                   mathjax = "default",
                                   template = "default",
                                   css = NULL,
                                   includes = NULL,
                                   keep_md = FALSE,
                                   lib_dir = NULL,
                                   pandoc_args = NULL,
                                   extra_dependencies = NULL,
                                   md_extensions = NULL,
                                   ...) {

   # base pandoc options for all reveal.js output
   args <- c()

   # table of contents
   args <- c(args, pandoc_toc_args(toc, toc_depth))

   # template path and assets
   if (identical(template, "default")) {
     default_template <- reveal_resources("default.html")
     args <- c(args, "--template", pandoc_path_arg(default_template))
   } else if (!is.null(template)) {
     args <- c(args, "--template", pandoc_path_arg(template))
   }

   # incremental
   if (incremental) args <- c(args, "--incremental")

   # centering
   args <- c(args, pandoc_variable_arg("center", jsbool(center)))

   # slide level
   args <- c(args, "--slide-level", as.character(slide_level))

   # theme
   theme <- match.arg(theme, revealjs_themes())
   if (identical(theme, "default")) {
     theme <- "simple"
   } else if (identical(theme, "dark")) {
     theme <- "black"
   }
   if (theme %in% c("blood", "moon", "night", "black")) {
     args <- c(args, pandoc_variable_arg("theme-dark"))
   }
   args <- c(args, pandoc_variable_arg("theme", theme))


   # transition
   transition <- match.arg(transition, revealjs_transitions())
   if (identical(transition, "default")) {
     # revealjs default is convex
     transition <- "convex"
   }
   args <- c(args, pandoc_variable_arg("transition", transition))

   # background_transition
   background_transition <- match.arg(background_transition, revealjs_transitions())
   if (identical(background_transition, "default")) {
     # revealjs default is fade
     background_transition <- "fade"
   }
   args <- c(args, pandoc_variable_arg("backgroundTransition", background_transition))

   # use history
   args <- c(args, pandoc_variable_arg("history", "true"))

   # additional reveal options
   if (is.list(reveal_options)) {
     for (option in names(reveal_options)) {
       # special handling for nested options
       if (option %in% c("chalkboard", "menu")) {
         nested_options <- reveal_options[[option]]
         for (nested_option in names(nested_options)) {
           args <- c(args,
                     process_reveal_option(
                       paste0(option, "-", nested_option),
                       nested_options[[nested_option]]
                     )
           )
         }
       } else {
         # standard top-level options
         args <- c(args, process_reveal_option(option, reveal_options[[option]]))
       }
     }
   }

   # reveal plugins
   if (is.character(reveal_plugins)) {

     # validate that we need to use self_contained for plugins
     if (self_contained) {
       stop("Using reveal_plugins requires self_contained: false")
     }

     # validate specified plugins are supported
     supported_plugins <- c("notes", "search", "zoom", "chalkboard", "menu")
     invalid_plugins <- setdiff(reveal_plugins, supported_plugins)
     if (length(invalid_plugins) > 0) {
       stop("The following plugin(s) are not supported: ",
         paste(invalid_plugins, collapse = ", "),
         call. = FALSE
       )
     }

     # add plugins
     if ("chalkboard" %in% reveal_plugins) {
       # chalkboard require customcontrols so we add it to activate in the template
       reveal_plugins <- c(reveal_plugins, "customcontrols")
     }
     sapply(reveal_plugins, function(plugin) {
       args <<- c(args, pandoc_variable_arg(paste0("plugin-", plugin)))
       if (plugin %in% c("customcontrols", "menu")) {
         extra_dependencies <<- append(
           extra_dependencies,
           list(rmarkdown::html_dependency_font_awesome())
         )
       }
     })
   }

   # content includes
   args <- c(args, includes_to_pandoc_args(includes))

   # additional css
   for (css_file in css) {
     args <- c(args, "--css", pandoc_path_arg(css_file))
   }

   # pre-processor for arguments that may depend on the name of the
   # the input file (e.g. ones that need to copy supporting files)
   pre_processor <- function(metadata, input_file, runtime, knit_meta, files_dir,
                             output_dir) {

     # we don't work with runtime shiny
     if (identical(runtime, "shiny")) {
       stop("revealjs_presentation is not compatible with runtime 'shiny'",
         call. = FALSE
       )
     }

     # use files_dir as lib_dir if not explicitly specified
     if (is.null(lib_dir)) {
       lib_dir <- files_dir
     }

     # extra args
     args <- c()

     # reveal.js
     revealjs_path <- revealjs_lib_path()
     if (!self_contained || identical(.Platform$OS.type, "windows")) {
       revealjs_path <- relative_to(
         output_dir, render_supporting_files(revealjs_path, lib_dir)
       )
     } else {
       revealjs_path <- pandoc_path_arg(revealjs_path)
     }
     args <- c(args, pandoc_variable_arg("revealjs-url", revealjs_path))

     # highlight
     args <- c(args, pandoc_highlight_args(highlight, default = "pygments"))

     # return additional args
     args
   }

   # return format
   output_format(
     knitr = knitr_options_html(fig_width, fig_height, fig_retina, keep_md),
     pandoc = pandoc_options(
       to = "revealjs",
       from = from_rmarkdown(fig_caption, md_extensions),
       args = args
     ),
     keep_md = keep_md,
     clean_supporting = self_contained,
     pre_processor = pre_processor,
     base_format = html_document_base(
       lib_dir = lib_dir,
       self_contained = self_contained,
       mathjax = mathjax,
       pandoc_args = pandoc_args,
       extra_dependencies = extra_dependencies,
       ...
     )
   )
 }

 revealjs_themes <- function() {
   c(
     "default", # not used by reveal
     "ids",
     "simple",
     "dark", # our alias for black
     "black",
     "sky",
     "beige",
     "serif",
     "solarized",
     "blood",
     "moon",
     "night",
     "league",
     "white"
   )
 }

 revealjs_transitions <- function() {
   c(
     "default", # not used by reveal
     "convex",
     "fade",
     "slide",
     "concave",
     "zoom",
     "none"
   )
 }
	#' Convert to a reveal.js presentation
	#'
	#' Format for converting from R Markdown to a reveal.js presentation.
	#'
	#' In reveal.js presentations you can use level 1 or level 2 headers for slides.
	#' If you use a mix of level 1 and level 2 headers then a two-dimensional layout
	#' will be produced, with level 1 headers building horizontally and level 2
	#' headers building vertically.
	#'
	#' For additional documentation on using revealjs presentations see
	#' <https://github.com/rstudio/revealjs>
	#'
	#' # About plugins
	#'
	#' ## Built-in plugins with reveal.js
	#'
	#' ### Zoom
	#'
	#' When activated, ALT + Click can be used to zoom on a slide.
	#'
	#' ### Notes
	#'
	#' Show a [speaker view](https://revealjs.com/speaker-view/) in a separated
	#' window. This speaker view contains a timer, current slide, next slide, and
	#' speaker notes. It also duplicate the window to have presentation mode
	#' synchronized with main presentation.
	#'
	#' Use
	#' ```markdown
	#' ::: notes
	#' Content of speaker notes
	#' :::
	#' ```
	#' to create notes only viewable in presentation mode.
	#'
	#' ### Search
	#'
	#' When opt-in, it is possible to show a search box when pressing `CTRL + SHIFT +
	#' F`. It will seach in the whole presentation, and highlight matched words. The
	#' matches will also be highlighted in overview mode (pressing ESC to see all
	#' slides in one scrollable view)
	#'
	#' ## Menu
	#'
	#' A slideout menu plugin for Reveal.js to quickly jump to any slide by title.
	#'
	#' Version `r version <- readLines(revealjs_lib_path("plugin", "menu", "VERSION"))` is
	#' currently used and documentation for configurations can be found at
	#' [denehyg/reveal.js-menu](https://github.com/denehyg/reveal.js-menu/blob/`r version`/README.md)
	#'
	#' ### Known limitations
	#'
	#' Some configurations cannot be modified in the current template:
	#'
	#' * `loadIcons: false` the fontawesome icons are loaded by \pkg{rmarkdown}
	#' when this plugin is used
	#' * `custom: false`
	#' * `themes: false`
	#' * `transitions: false`

	#' ## Chalkboard
	#'
	#' A plugin adding a chalkboard and slide annotation
	#'
	#' Version `r version <- readLines(revealjs_lib_path("plugin", "chalkboard", "VERSION"))` is
	#' currently used and documentation for configurations can be found at
	#' [rajgoel/reveal.js-plugins](https://github.com/rajgoel/reveal.js-plugins/tree/`r version`/4.1.5/chalkboard)
	#'
	#' By default, chalkboard and annotations modes will be accessible using keyboard
	#' shortcuts, respectively, pressing B, or pressing C.
	#' In addition, buttons on the bottom left can be added by using the following
	#'
	#' ```yaml
	#' reveal_plugins:
	#' - chalkboard
	#' reveal_options:
	#' chalkboard:
	#' toggleNotesButton: true
	#' toggleChalkboardButton: true
	#' ```
	#' @inheritParams rmarkdown::beamer_presentation
	#' @inheritParams rmarkdown::pdf_document
	#' @inheritParams rmarkdown::html_document
	#'
	#' @param center `TRUE` to vertically center content on slides
	#' @param slide_level Level of heading to denote individual slides. If
	#' `slide_level` is 2 (the default), a two-dimensional layout will be
	#' produced, with level 1 headers building horizontally and level 2 headers
	#' building vertically. It is not recommended that you use deeper nesting of
	#' section levels with reveal.js.
	#' @param theme Visual theme (`r knitr::combine_words(setdiff(revealjs_themes(), "default"), before = '"', and = " or ")`)
	#' @param transition Slide transition (
	#' `r (trans <- knitr::combine_words(setdiff(revealjs_transitions(), "default"), before = '"', and = " or "))`
	#' )
	#' @param background_transition Slide background-transition (
	#' `r trans`
	#' )
	#' @param reveal_options Additional options to specify for reveal.js (see
	#' <https://revealjs.com/config/> for details). Options for plugins can also
	#' be passed, using plugin name as first level key (e.g `list(slideNumber =
	#' FALSE, menu = list(number = TRUE))`).
	#' @param reveal_plugins Reveal plugins to include. Available plugins include
	#' "notes", "search", "zoom", "chalkboard", and "menu". Note that
	#' `self_contained` must be set to `FALSE` in order to use Reveal
	#' plugins.
	#' @param template Pandoc template to use for rendering. Pass "default" to use
	#' the rmarkdown package default template; pass `NULL` to use pandoc's
	#' built-in template; pass a path to use a custom template that you've
	#' created. Note that if you don't use the "default" template then some
	#' features of `revealjs_presentation` won't be available (see the
	#' Templates section below for more details).
	#' @param extra_dependencies Additional function arguments to pass to the base R
	#' Markdown HTML output formatter [rmarkdown::html_document_base()].
	#' @param ... Ignored
	#'
	#' @return R Markdown output format to pass to [rmarkdown::render()]
	#'
	#' @examples
	#' \dontrun{
	#'
	#' library(rmarkdown)
	#' library(revealjs)
	#'
	#' # simple invocation
	#' render("pres.Rmd", revealjs_presentation())
	#'
	#' # specify an option for incremental rendering
	#' render("pres.Rmd", revealjs_presentation(incremental = TRUE))
	#' }
	#'
	#' @export
	revealjs_presentation <- function(incremental = FALSE,
	center = FALSE,
	slide_level = 2,
	toc = FALSE,
	toc_depth = 3,
	fig_width = 8,
	fig_height = 6,
	fig_retina = if (!fig_caption) 2,
	fig_caption = FALSE,
	self_contained = TRUE,
	theme = "simple",
	transition = "convex",
	background_transition = "fade",
	reveal_options = NULL,
	reveal_plugins = NULL,
	highlight = "default",
	mathjax = "default",
	template = "default",
	css = NULL,
	includes = NULL,
	keep_md = FALSE,
	lib_dir = NULL,
	pandoc_args = NULL,
	extra_dependencies = NULL,
	md_extensions = NULL,
	...) {

	# base pandoc options for all reveal.js output
	args <- c()

	# table of contents
	args <- c(args, pandoc_toc_args(toc, toc_depth))

	# template path and assets
	if (identical(template, "default")) {
	default_template <- reveal_resources("default.html")
	args <- c(args, "--template", pandoc_path_arg(default_template))
	} else if (!is.null(template)) {
	args <- c(args, "--template", pandoc_path_arg(template))
	}

	# incremental
	if (incremental) args <- c(args, "--incremental")

	# centering
	args <- c(args, pandoc_variable_arg("center", jsbool(center)))

	# slide level
	args <- c(args, "--slide-level", as.character(slide_level))

	# theme
	theme <- match.arg(theme, revealjs_themes())
	if (identical(theme, "default")) {
	theme <- "simple"
	} else if (identical(theme, "dark")) {
	theme <- "black"
	}
	if (theme %in% c("blood", "moon", "night", "black")) {
	args <- c(args, pandoc_variable_arg("theme-dark"))
	}
	args <- c(args, pandoc_variable_arg("theme", theme))


	# transition
	transition <- match.arg(transition, revealjs_transitions())
	if (identical(transition, "default")) {
	# revealjs default is convex
	transition <- "convex"
	}
	args <- c(args, pandoc_variable_arg("transition", transition))

	# background_transition
	background_transition <- match.arg(background_transition, revealjs_transitions())
	if (identical(background_transition, "default")) {
	# revealjs default is fade
	background_transition <- "fade"
	}
	args <- c(args, pandoc_variable_arg("backgroundTransition", background_transition))

	# use history
	args <- c(args, pandoc_variable_arg("history", "true"))

	# additional reveal options
	if (is.list(reveal_options)) {
	for (option in names(reveal_options)) {
	# special handling for nested options
	if (option %in% c("chalkboard", "menu")) {
	nested_options <- reveal_options[[option]]
	for (nested_option in names(nested_options)) {
	args <- c(args,
	process_reveal_option(
	paste0(option, "-", nested_option),
	nested_options[[nested_option]]
	)
	)
	}
	} else {
	# standard top-level options
	args <- c(args, process_reveal_option(option, reveal_options[[option]]))
	}
	}
	}

	# reveal plugins
	if (is.character(reveal_plugins)) {

	# validate that we need to use self_contained for plugins
	if (self_contained) {
	stop("Using reveal_plugins requires self_contained: false")
	}

	# validate specified plugins are supported
	supported_plugins <- c("notes", "search", "zoom", "chalkboard", "menu")
	invalid_plugins <- setdiff(reveal_plugins, supported_plugins)
	if (length(invalid_plugins) > 0) {
	stop("The following plugin(s) are not supported: ",
	paste(invalid_plugins, collapse = ", "),
	call. = FALSE
	)
	}

	# add plugins
	if ("chalkboard" %in% reveal_plugins) {
	# chalkboard require customcontrols so we add it to activate in the template
	reveal_plugins <- c(reveal_plugins, "customcontrols")
	}
	sapply(reveal_plugins, function(plugin) {
	args <<- c(args, pandoc_variable_arg(paste0("plugin-", plugin)))
	if (plugin %in% c("customcontrols", "menu")) {
	extra_dependencies <<- append(
	extra_dependencies,
	list(rmarkdown::html_dependency_font_awesome())
	)
	}
	})
	}

	# content includes
	args <- c(args, includes_to_pandoc_args(includes))

	# additional css
	for (css_file in css) {
	args <- c(args, "--css", pandoc_path_arg(css_file))
	}

	# pre-processor for arguments that may depend on the name of the
	# the input file (e.g. ones that need to copy supporting files)
	pre_processor <- function(metadata, input_file, runtime, knit_meta, files_dir,
	output_dir) {

	# we don't work with runtime shiny
	if (identical(runtime, "shiny")) {
	stop("revealjs_presentation is not compatible with runtime 'shiny'",
	call. = FALSE
	)
	}

	# use files_dir as lib_dir if not explicitly specified
	if (is.null(lib_dir)) {
	lib_dir <- files_dir
	}

	# extra args
	args <- c()

	# reveal.js
	revealjs_path <- revealjs_lib_path()
	if (!self_contained \|\| identical(.Platform$OS.type, "windows")) {
	revealjs_path <- relative_to(
	output_dir, render_supporting_files(revealjs_path, lib_dir)
	)
	} else {
	revealjs_path <- pandoc_path_arg(revealjs_path)
	}
	args <- c(args, pandoc_variable_arg("revealjs-url", revealjs_path))

	# highlight
	args <- c(args, pandoc_highlight_args(highlight, default = "pygments"))

	# return additional args
	args
	}

	# return format
	output_format(
	knitr = knitr_options_html(fig_width, fig_height, fig_retina, keep_md),
	pandoc = pandoc_options(
	to = "revealjs",
	from = from_rmarkdown(fig_caption, md_extensions),
	args = args
	),
	keep_md = keep_md,
	clean_supporting = self_contained,
	pre_processor = pre_processor,
	base_format = html_document_base(
	lib_dir = lib_dir,
	self_contained = self_contained,
	mathjax = mathjax,
	pandoc_args = pandoc_args,
	extra_dependencies = extra_dependencies,
	...
	)
	)
	}

	revealjs_themes <- function() {
	c(
	"default", # not used by reveal
	"ids",
	"simple",
	"dark", # our alias for black
	"black",
	"sky",
	"beige",
	"serif",
	"solarized",
	"blood",
	"moon",
	"night",
	"league",
	"white"
	)
	}

	revealjs_transitions <- function() {
	c(
	"default", # not used by reveal
	"convex",
	"fade",
	"slide",
	"concave",
	"zoom",
	"none"
	)
	}