solr/solr-ref-guide/src/_templates/helpers.rb - lucene-solr - Git at Google

 require 'date' unless RUBY_PLATFORM == 'opal'

 # Add custom functions to this module that you want to use in your Slim
 # templates. Within the template you can invoke them as top-level functions
 # just like in Haml.
 module Slim::Helpers

   # URIs of external assets.
   FONT_AWESOME_URI     = '//cdn.jsdelivr.net/npm/font-awesome@4.7.0/css/font-awesome.min.css'
   HIGHLIGHTJS_BASE_URI = '//cdn.jsdelivr.net/gh/highlightjs/cdn-release@9.12.0/build/'
   KATEX_CSS_URI        = '//cdn.jsdelivr.net/npm/katex@0.8.3/dist/katex.min.css'
   KATEX_JS_URI         = '//cdn.jsdelivr.net/npm/katex@0.8.3/dist/katex.min.js'

   # Defaults
   DEFAULT_HIGHLIGHTJS_THEME = 'github'
   DEFAULT_SECTNUMLEVELS = 3
   DEFAULT_TOCLEVELS = 2

   KATEX_RENDER_CODE = <<-JS.gsub(/\s+/, ' ')
     document.addEventListener("DOMContentLoaded", function() {
       var elements = document.getElementsByClassName("math");
       for (var i = 0; i < elements.length; i++) {
         var el = elements[i];
         if (el.getAttribute("data-lang") !== "tex") {
           continue;
         }
         katex.render(el.textContent.slice(2, -2), el, {
           "displayMode": el.nodeName.toUpperCase() !== "SPAN",
           "throwOnError": false,
         });
       }
     });
   JS

   VOID_ELEMENTS = %w(area base br col command embed hr img input keygen link
                      meta param source track wbr)


   # @return [Logger]
   def log
     @_html5s_logger ||= ::Asciidoctor::Html5s::Logging.default_logger
   end

   ##
   # Captures the given block for later yield.
   #
   # @example Basic capture usage.
   #   - capture
   #     img src=image_uri
   #   - if title?
   #     figure.image
   #       - yield_capture
   #       figcaption =captioned_title
   #   - else
   #     - yield_capture
   #
   # @example Capture with passing parameters.
   #   - capture do |id|
   #     img src=image_uri
   #   - if title?
   #     figure id=@id
   #       - yield_capture
   #       figcaption =caption
   #   - else
   #     - yield_capture @id
   #
   # @see yield_capture
   def capture(&block)
     @_html5s_capture = block
     nil
   end

   ##
   # Yields the captured block (see {#capture}).
   #
   # @param *params parameters to pass to the block.
   # @return A content of the captured block.
   # @see capture
   def yield_capture(*params)
     @_html5s_capture.call(*params) if @_html5s_capture
   end

   ##
   # Creates an HTML tag with the given name and optionally attributes. Can take
   # a block that will run between the opening and closing tags.
   #
   # @param name [#to_s] the name of the tag.
   # @param attributes [Hash] (default: {})
   # @param content [#to_s] the content; +nil+ to call the block. (default: nil).
   # @yield The block of Slim/HTML code within the tag (optional).
   # @return [String] a rendered HTML element.
   #
   def html_tag(name, attributes = {}, content = nil)
     attrs = attributes.inject([]) do |attrs, (k, v)|
       next attrs if !v || v.nil_or_empty?
       v = v.compact.join(' ') if v.is_a? Array
       attrs << (v == true ? k : %(#{k}="#{v}"))
     end
     attrs_str = attrs.empty? ? '' : ' ' + attrs.join(' ')

     if VOID_ELEMENTS.include? name.to_s
       %(<#{name}#{attrs_str}>)
     else
       content ||= yield if block_given?
       %(<#{name}#{attrs_str}>#{content}</#{name}>)
     end
   end

   ##
   # Conditionally wraps a block in an element. If condition is +true+ then it
   # renders the specified tag with optional attributes and the given
   # block inside, otherwise it just renders the block.
   #
   # For example:
   #
   #    = html_tag_if link?, 'a', {class: 'image', href: (attr :link)}
   #      img src='./img/tux.png'
   #
   # will produce:
   #
   #    <a href="http://example.org" class="image">
   #      <img src="./img/tux.png">
   #    </a>
   #
   # if +link?+ is truthy, and just
   #
   #   <img src="./img/tux.png">
   #
   # otherwise.
   #
   # @param condition [Boolean] the condition to test to determine whether to
   #        render the enclosing tag.
   # @param name (see #html_tag)
   # @param attributes (see #html_tag)
   # @param content (see #html_tag)
   # @yield (see #html_tag)
   # @return [String] a rendered HTML fragment.
   #
   def html_tag_if(condition, name, attributes = {}, content = nil, &block)
     if condition
       html_tag name, attributes, content, &block
     else
       content || yield
     end
   end

   ##
   # Wraps a block in a div element with the specified class and optionally
   # the node's +id+ and +role+(s). If the node's +title+ is not empty, then a
   # nested div with the class "title" and the title's content is added as well.
   #
   # @example When @id, @role and @title attributes are set.
   #   = block_with_title :class=>['quote-block', 'center']
   #     blockquote =content
   #
   #   <section id="myid" class="quote-block center myrole1 myrole2">
   #     <h6>Block Title</h6>
   #     <blockquote>Lorem ipsum</blockquote>
   #   </section>
   #
   # @example When @id, @role and @title attributes are empty.
   #   = block_with_title :class=>'quote-block center', :style=>style_value(float: 'left')
   #     blockquote =content
   #
   #   <div class="quote-block center" style="float: left;">
   #     <blockquote>Lorem ipsum</blockquote>
   #   </div>
   #
   # @example When shorthand style for class attribute is used.
   #   = block_with_title 'quote-block center'
   #     blockquote =content
   #
   #   <div class="quote-block center">
   #     <blockquote>Lorem ipsum</blockquote>
   #   </div>
   #
   # @param attrs [Hash, String] the tag's attributes as Hash),
   #        or the tag's class if it's not a Hash.
   # @param title [String, nil] the title.
   # @yield The block of Slim/HTML code within the tag (optional).
   # @return [String] a rendered HTML fragment.
   #
   def block_with_title(attrs = {}, title = @title, &block)
     if (klass = attrs[:class]).is_a? String
       klass = klass.split(' ')
     end
     attrs[:class] = [klass, role].flatten.uniq
     attrs[:id] = id

     if title.nil_or_empty?
       # XXX quick hack
       nested = is_a?(::Asciidoctor::List) &&
           (parent.is_a?(::Asciidoctor::ListItem) || parent.is_a?(::Asciidoctor::List))
       html_tag_if !nested, :div, attrs, yield
     else
       html_tag :section, attrs do
         [html_tag(:h6, {class: 'block-title'}, title), yield].join("\n")
       end
     end
   end

   def block_with_caption(position = :bottom, attrs = {}, &block)
     if (klass = attrs[:class]).is_a? String
       klass = klass.split(' ')
     end
     attrs[:class] = [klass, role].flatten.uniq
     attrs[:id] = id

     if title.nil_or_empty?
       html_tag :div, attrs, yield
     else
       html_tag :figure, attrs do
         ary = [yield, html_tag(:figcaption) { captioned_title }]
         ary.reverse! if position == :top
         ary.compact.join("\n")
       end
     end
   end

   ##
   # Delimite the given equation as a STEM of the specified type.
   #
   # Note: This is not needed nor used for KaTeX, but keep this for the case
   # user wants to use a different method.
   #
   # @param equation [String] the equation to delimite.
   # @param type [#to_sym] the type of the STEM renderer (latexmath, or asciimath).
   # @return [String] the delimited equation.
   #
   def delimit_stem(equation, type)
     if (@_html5s_stem_type ||= document.attr('html5s-force-stem-type'))
       type = @_html5s_stem_type
     end

     if is_a? ::Asciidoctor::Block
       open, close = ::Asciidoctor::BLOCK_MATH_DELIMITERS[type.to_sym]
     else
       open, close = ::Asciidoctor::INLINE_MATH_DELIMITERS[type.to_sym]
     end

     if !equation.start_with?(open) || !equation.end_with?(close)
       equation = [open, equation, close].join
     end
     equation
   end

   ##
   # Formats the given hash as CSS declarations for an inline style.
   #
   # @example
   #   style_value(text_align: 'right', float: 'left')
   #   => "text-align: right; float: left;"
   #
   #   style_value(text_align: nil, float: 'left')
   #   => "float: left;"
   #
   #   style_value(width: [90, '%'], height: '50px')
   #   => "width: 90%; height: 50px;"
   #
   #   style_value(width: ['120px', 'px'])
   #   => "width: 90px;"
   #
   #   style_value(width: [nil, 'px'])
   #   => nil
   #
   # @param declarations [Hash]
   # @return [String, nil]
   #
   def style_value(declarations)
     decls = []

     declarations.each do |prop, value|
       next if value.nil?

       if value.is_a? Array
         value, unit = value
         next if value.nil?
         value = value.to_s + unit unless value.end_with? unit
       end
       prop = prop.to_s.gsub('_', '-')
       decls << "#{prop}: #{value}"
     end

     decls.empty? ? nil : decls.join('; ') + ';'
   end

   def urlize(*segments)
     path = segments * '/'
     if path.start_with? '//'
       @_html5s_uri_scheme ||= document.attr('asset-uri-scheme', 'https')
       path = "#{@_html5s_uri_scheme}:#{path}" unless @_html5s_uri_scheme.empty?
     end
     normalize_web_path path
   end


   ##
   # Gets the value of the specified attribute in this node.
   #
   # This is just an alias for +attr+ method with disabled _inherit_ to make it
   # more clear.
   #
   # @param name [String, Symbol] the name of the attribute to lookup.
   # @param default_val the value to return if the attribute is not found.
   # @return value of the attribute or +default_val+ if not found.
   #
   def local_attr(name, default_val = nil)
     attr(name, default_val, false)
   end

   ##
   # Checks if the attribute is defined on this node, optionally performing
   # a comparison of its value if +expect_val+ is not nil.
   #
   # This is just an alias for +attr?+ method with disabled _inherit_ to make it
   # more clear.
   #
   # @param name [String, Symbol] the name of the attribute to lookup.
   # @param default_val the expected value of the attribute.
   # @return [Boolean] whether the attribute exists and, if +expect_val+ is
   #   specified, whether the value of the attribute matches the +expect_val+.
   #
   def local_attr?(name, expect_val = nil)
     attr?(name, expect_val, false)
   end

   ##
   # @param index [Integer] the footnote's index.
   # @return [String] footnote id to be used in a link.
   def footnote_id(index = local_attr(:index))
     "_footnote_#{index}"
   end

   ##
   # @param index (see #footnote_id)
   # @return [String] footnoteref id to be used in a link.
   def footnoteref_id(index = local_attr(:index))
     "_footnoteref_#{index}"
   end

   def nowrap?
     'nowrap' if !document.attr?(:prewrap) || option?('nowrap')
   end

   def print_item_content(item)
     wrap = item.blocks? && !item.blocks.all? { |b| b.is_a? ::Asciidoctor::List }
     [ (html_tag_if(wrap, :p) { item.text } if item.text?), item.content ].join
   end

   ##
   # Returns corrected section level.
   #
   # @param sec [Asciidoctor::Section] the section node (default: self).
   # @return [Integer]
   #
   def section_level(sec = self)
     (sec.level == 0 && sec.special) ? 1 : sec.level
   end

   ##
   # Returns the captioned section's title, optionally numbered.
   #
   # @param sec [Asciidoctor::Section] the section node (default: self).
   # @return [String]
   #
   def section_title(sec = self)
     sectnumlevels = document.attr(:sectnumlevels, DEFAULT_SECTNUMLEVELS).to_i

     if sec.numbered && !sec.caption && sec.level <= sectnumlevels
       [sec.sectnum, sec.captioned_title].join(' ')
     else
       sec.captioned_title
     end
   end

   ##
   # @return [String] language of STEM block or inline node (tex or asciimath).
   def stem_lang
     value = (inline? ? type : style).to_s
     value == 'latexmath' ? 'tex' : value
   end

   def link_rel
     'noopener' if option?('noopener') || attr(:window) == '_blank'
   end

   #--------------------------------------------------------
   # block_admonition
   #

   ##
   # @return [Boolean] should be this admonition wrapped in aside element?
   def admonition_aside?
     %w[note tip].include? attr(:name)
   end

   ##
   # @return [String, nil] WAI-ARIA role of this admonition.
   def admonition_aria
     case attr(:name)
     when 'note'
       'note'  # https://www.w3.org/TR/wai-aria/roles#note
     when 'tip'
       'doc-tip'  # https://www.w3.org/TR/dpub-aria-1.0/#doc-tip
     when 'caution', 'important', 'warning'
       'doc-notice'  # https://www.w3.org/TR/dpub-aria-1.0/#doc-notice
     end
   end

   #--------------------------------------------------------
   # block_listing
   #

   ##
   # @return [String] a canonical name of the source-highlighter to be used as
   #         a style class.
   def highlighter
     @_html5s_highlighter ||=
       case (highlighter = document.attr('source-highlighter'))
       when 'coderay'; 'CodeRay'
       when 'highlight.js'; 'highlightjs'
       else highlighter
       end
   end

   ##
   # Returns the callout list attached to this listing node, or +nil+ if none.
   #
   # Note: This variable is set by extension
   # {Asciidoctor::Html5s::AttachedColistTreeprocessor}.
   #
   # @return [Asciidoctor::List, nil]
   def callout_list
     @html5s_colist
   end

   def source_lang
     local_attr :language, false
   end

   #--------------------------------------------------------
   # block_open
   #

   ##
   # Returns +true+ if an abstract block is allowed in this document type,
   # otherwise prints warning and returns +false+.
   def abstract_allowed?
     if result = (parent == document && document.doctype == 'book')
       log.warn 'asciidoctor: WARNING: abstract block cannot be used in a document
 without a title when doctype is book. Excluding block content.'
     end
     !result
   end

   ##
   # Returns +true+ if a partintro block is allowed in this context, otherwise
   # prints warning and returns +false+.
   def partintro_allowed?
     if result = (level != 0 || parent.context != :section || document.doctype != 'book')
       log.warn "asciidoctor: ERROR: partintro block can only be used when doctype
 is book and it's a child of a book part. Excluding block content."
     end
     !result
   end

   #--------------------------------------------------------
   # block_table
   #

   def autowidth?
     option? :autowidth
   end

   def spread?
     if !autowidth? || local_attr?('width')
       'spread' if attr? :tablepcwidth, 100
     end
   end

   #--------------------------------------------------------
   # block_video
   #

   # @return [Boolean] +true+ if the video should be embedded in an iframe.
   def video_iframe?
     ['vimeo', 'youtube'].include? attr(:poster)
   end

   def video_uri
     case attr(:poster, '').to_sym
     when :vimeo
       params = {
         autoplay: (1 if option? 'autoplay'),
         loop:     (1 if option? 'loop')
       }
       start_anchor = "#at=#{attr :start}" if attr? :start
       "//player.vimeo.com/video/#{attr :target}#{start_anchor}#{url_query params}"

     when :youtube
       video_id, list_id = attr(:target).split('/', 2)
       params = {
         rel:      0,
         start:    (attr :start),
         end:      (attr :end),
         list:     (attr :list, list_id),
         autoplay: (1 if option? 'autoplay'),
         loop:     (1 if option? 'loop'),
         controls: (0 if option? 'nocontrols')
       }
       "//www.youtube.com/embed/#{video_id}#{url_query params}"
     else
       anchor = [attr(:start), attr(:end)].join(',').chomp(',')
       anchor = '#t=' + anchor unless anchor.empty?
       media_uri "#{attr :target}#{anchor}"
     end
   end

   # Formats URL query parameters.
   def url_query(params)
     str = params.map { |k, v|
       next if v.nil? || v.to_s.empty?
       [k, v] * '='
     }.compact.join('&amp;')

     '?' + str unless str.empty?
   end

   #--------------------------------------------------------
   # document
   #

   ##
   # @return [String, nil] the revision date in ISO 8601, or nil if not
   #   available or in invalid format.
   def revdate_iso
     ::Date.parse(revdate).iso8601 if defined? ::Date
   rescue ArgumentError
     nil
   end

   ##
   # Returns HTML meta tag if the given +content+ is not +nil+.
   #
   # @param name [#to_s] the name for the metadata.
   # @param content [#to_s, nil] the value of the metadata, or +nil+.
   # @return [String, nil] the meta tag, or +nil+ if the +content+ is +nil+.
   #
   def html_meta_if(name, content)
     %(<meta name="#{name}" content="#{content}">) if content
   end

   # Returns formatted style/link and script tags for header.
   def styles_and_scripts
     scripts = []
     styles = []
     tags = []

     stylesheet = attr :stylesheet
     stylesdir = attr :stylesdir, ''
     default_style = ::Asciidoctor::DEFAULT_STYLESHEET_KEYS.include? stylesheet
     linkcss = attr?(:linkcss) || safe >= ::Asciidoctor::SafeMode::SECURE
     ss = ::Asciidoctor::Stylesheets.instance

     if linkcss
       path = default_style ? ::Asciidoctor::DEFAULT_STYLESHEET_NAME : stylesheet
       styles << { href: [stylesdir, path] }
     elsif default_style
       styles << { text: ss.primary_stylesheet_data }
     else
       styles << { text: read_asset(normalize_system_path(stylesheet, stylesdir), true) }
     end

     if attr? :icons, 'font'
       if attr? 'iconfont-remote'
         styles << { href: attr('iconfont-cdn', FONT_AWESOME_URI) }
       else
         styles << { href: [stylesdir, "#{attr 'iconfont-name', 'font-awesome'}.css"] }
       end
     end

     if attr? 'stem'
       styles << { href: KATEX_CSS_URI }
       scripts << { src: KATEX_JS_URI }
       scripts << { text: KATEX_RENDER_CODE }
     end

     case attr 'source-highlighter'
     when 'coderay'
       if attr('coderay-css', 'class') == 'class'
         if linkcss
           styles << { href: [stylesdir, ss.coderay_stylesheet_name] }
         else
           styles << { text: ss.coderay_stylesheet_data }
         end
       end

     when 'highlightjs'
       hjs_base = attr :highlightjsdir, HIGHLIGHTJS_BASE_URI
       hjs_theme = attr 'highlightjs-theme', DEFAULT_HIGHLIGHTJS_THEME

       scripts << { src: [hjs_base, 'highlight.min.js'] }
       scripts << { text: 'hljs.initHighlightingOnLoad()' }
       styles  << { href: [hjs_base, "styles/#{hjs_theme}.min.css"] }
     end

     styles.each do |item|
       if item.key?(:text)
         tags << html_tag(:style) { item[:text] }
       else
         tags << html_tag(:link, rel: 'stylesheet', href: urlize(*item[:href]))
       end
     end

     scripts.each do |item|
       if item.key? :text
         tags << html_tag(:script, type: item[:type]) { item[:text] }
       else
         tags << html_tag(:script, type: item[:type], src: urlize(*item[:src]))
       end
     end

     tags.join("\n")
   end

   #--------------------------------------------------------
   # inline_anchor
   #

   # @return [String] text of the xref anchor.
   def xref_text
     str =
       if text
         text
       elsif (path = local_attr :path)
         path
       elsif document.respond_to? :catalog  # Asciidoctor >=1.5.6
         ref = document.catalog[:refs][attr :refid]
         if ref.kind_of? Asciidoctor::AbstractNode
           ref.xreftext((@_html5s_xrefstyle ||= document.attributes['xrefstyle']))
         end
       else  # Asciidoctor < 1.5.6
         document.references[:ids][attr :refid || target]
       end
     (str || "[#{attr :refid}]").tr_s("\n", ' ')
   end

   # @return [String, nil] text of the bibref anchor, or +nil+ if not found.
   def bibref_text
     if document.respond_to? :catalog  # Asciidoctor >=1.5.6
       # NOTE: Technically it should be `reftext`, but subs have already been applied to text.
       text
     else
       "[#{target}]"
     end
   end

   #--------------------------------------------------------
   # inline_image
   #

   # @return [Array] style classes for a Font Awesome icon.
   def icon_fa_classes
     [ "fa fa-#{target}",
       ("fa-#{attr :size}" if attr? :size),
       ("fa-rotate-#{attr :rotate}" if attr? :rotate),
       ("fa-flip-#{attr :flip}" if attr? :flip)
     ].compact
   end
 end
	require 'date' unless RUBY_PLATFORM == 'opal'

	# Add custom functions to this module that you want to use in your Slim
	# templates. Within the template you can invoke them as top-level functions
	# just like in Haml.
	module Slim::Helpers

	# URIs of external assets.
	FONT_AWESOME_URI = '//cdn.jsdelivr.net/npm/font-awesome@4.7.0/css/font-awesome.min.css'
	HIGHLIGHTJS_BASE_URI = '//cdn.jsdelivr.net/gh/highlightjs/cdn-release@9.12.0/build/'
	KATEX_CSS_URI = '//cdn.jsdelivr.net/npm/katex@0.8.3/dist/katex.min.css'
	KATEX_JS_URI = '//cdn.jsdelivr.net/npm/katex@0.8.3/dist/katex.min.js'

	# Defaults
	DEFAULT_HIGHLIGHTJS_THEME = 'github'
	DEFAULT_SECTNUMLEVELS = 3
	DEFAULT_TOCLEVELS = 2

	KATEX_RENDER_CODE = <<-JS.gsub(/\s+/, ' ')
	document.addEventListener("DOMContentLoaded", function() {
	var elements = document.getElementsByClassName("math");
	for (var i = 0; i < elements.length; i++) {
	var el = elements[i];
	if (el.getAttribute("data-lang") !== "tex") {
	continue;
	}
	katex.render(el.textContent.slice(2, -2), el, {
	"displayMode": el.nodeName.toUpperCase() !== "SPAN",
	"throwOnError": false,
	});
	}
	});
	JS

	VOID_ELEMENTS = %w(area base br col command embed hr img input keygen link
	meta param source track wbr)


	# @return [Logger]
	def log
	@_html5s_logger \|\|= ::Asciidoctor::Html5s::Logging.default_logger
	end

	##
	# Captures the given block for later yield.
	#
	# @example Basic capture usage.
	# - capture
	# img src=image_uri
	# - if title?
	# figure.image
	# - yield_capture
	# figcaption =captioned_title
	# - else
	# - yield_capture
	#
	# @example Capture with passing parameters.
	# - capture do \|id\|
	# img src=image_uri
	# - if title?
	# figure id=@id
	# - yield_capture
	# figcaption =caption
	# - else
	# - yield_capture @id
	#
	# @see yield_capture
	def capture(&block)
	@_html5s_capture = block
	nil
	end

	##
	# Yields the captured block (see {#capture}).
	#
	# @param *params parameters to pass to the block.
	# @return A content of the captured block.
	# @see capture
	def yield_capture(*params)
	@_html5s_capture.call(*params) if @_html5s_capture
	end

	##
	# Creates an HTML tag with the given name and optionally attributes. Can take
	# a block that will run between the opening and closing tags.
	#
	# @param name [#to_s] the name of the tag.
	# @param attributes [Hash] (default: {})
	# @param content [#to_s] the content; +nil+ to call the block. (default: nil).
	# @yield The block of Slim/HTML code within the tag (optional).
	# @return [String] a rendered HTML element.
	#
	def html_tag(name, attributes = {}, content = nil)
	attrs = attributes.inject([]) do \|attrs, (k, v)\|
	next attrs if !v \|\| v.nil_or_empty?
	v = v.compact.join(' ') if v.is_a? Array
	attrs << (v == true ? k : %(#{k}="#{v}"))
	end
	attrs_str = attrs.empty? ? '' : ' ' + attrs.join(' ')

	if VOID_ELEMENTS.include? name.to_s
	%(<#{name}#{attrs_str}>)
	else
	content \|\|= yield if block_given?
	%(<#{name}#{attrs_str}>#{content}</#{name}>)
	end
	end

	##
	# Conditionally wraps a block in an element. If condition is +true+ then it
	# renders the specified tag with optional attributes and the given
	# block inside, otherwise it just renders the block.
	#
	# For example:
	#
	# = html_tag_if link?, 'a', {class: 'image', href: (attr :link)}
	# img src='./img/tux.png'
	#
	# will produce:
	#
	# <a href="http://example.org" class="image">
	# <img src="./img/tux.png">
	# </a>
	#
	# if +link?+ is truthy, and just
	#
	# <img src="./img/tux.png">
	#
	# otherwise.
	#
	# @param condition [Boolean] the condition to test to determine whether to
	# render the enclosing tag.
	# @param name (see #html_tag)
	# @param attributes (see #html_tag)
	# @param content (see #html_tag)
	# @yield (see #html_tag)
	# @return [String] a rendered HTML fragment.
	#
	def html_tag_if(condition, name, attributes = {}, content = nil, &block)
	if condition
	html_tag name, attributes, content, &block
	else
	content \|\| yield
	end
	end

	##
	# Wraps a block in a div element with the specified class and optionally
	# the node's +id+ and +role+(s). If the node's +title+ is not empty, then a
	# nested div with the class "title" and the title's content is added as well.
	#
	# @example When @id, @role and @title attributes are set.
	# = block_with_title :class=>['quote-block', 'center']
	# blockquote =content
	#
	# <section id="myid" class="quote-block center myrole1 myrole2">
	# <h6>Block Title</h6>
	# <blockquote>Lorem ipsum</blockquote>
	# </section>
	#
	# @example When @id, @role and @title attributes are empty.
	# = block_with_title :class=>'quote-block center', :style=>style_value(float: 'left')
	# blockquote =content
	#
	# <div class="quote-block center" style="float: left;">
	# <blockquote>Lorem ipsum</blockquote>
	# </div>
	#
	# @example When shorthand style for class attribute is used.
	# = block_with_title 'quote-block center'
	# blockquote =content
	#
	# <div class="quote-block center">
	# <blockquote>Lorem ipsum</blockquote>
	# </div>
	#
	# @param attrs [Hash, String] the tag's attributes as Hash),
	# or the tag's class if it's not a Hash.
	# @param title [String, nil] the title.
	# @yield The block of Slim/HTML code within the tag (optional).
	# @return [String] a rendered HTML fragment.
	#
	def block_with_title(attrs = {}, title = @title, &block)
	if (klass = attrs[:class]).is_a? String
	klass = klass.split(' ')
	end
	attrs[:class] = [klass, role].flatten.uniq
	attrs[:id] = id

	if title.nil_or_empty?
	# XXX quick hack
	nested = is_a?(::Asciidoctor::List) &&
	(parent.is_a?(::Asciidoctor::ListItem) \|\| parent.is_a?(::Asciidoctor::List))
	html_tag_if !nested, :div, attrs, yield
	else
	html_tag :section, attrs do
	[html_tag(:h6, {class: 'block-title'}, title), yield].join("\n")
	end
	end
	end

	def block_with_caption(position = :bottom, attrs = {}, &block)
	if (klass = attrs[:class]).is_a? String
	klass = klass.split(' ')
	end
	attrs[:class] = [klass, role].flatten.uniq
	attrs[:id] = id

	if title.nil_or_empty?
	html_tag :div, attrs, yield
	else
	html_tag :figure, attrs do
	ary = [yield, html_tag(:figcaption) { captioned_title }]
	ary.reverse! if position == :top
	ary.compact.join("\n")
	end
	end
	end

	##
	# Delimite the given equation as a STEM of the specified type.
	#
	# Note: This is not needed nor used for KaTeX, but keep this for the case
	# user wants to use a different method.
	#
	# @param equation [String] the equation to delimite.
	# @param type [#to_sym] the type of the STEM renderer (latexmath, or asciimath).
	# @return [String] the delimited equation.
	#
	def delimit_stem(equation, type)
	if (@_html5s_stem_type \|\|= document.attr('html5s-force-stem-type'))
	type = @_html5s_stem_type
	end

	if is_a? ::Asciidoctor::Block
	open, close = ::Asciidoctor::BLOCK_MATH_DELIMITERS[type.to_sym]
	else
	open, close = ::Asciidoctor::INLINE_MATH_DELIMITERS[type.to_sym]
	end

	if !equation.start_with?(open) \|\| !equation.end_with?(close)
	equation = [open, equation, close].join
	end
	equation
	end

	##
	# Formats the given hash as CSS declarations for an inline style.
	#
	# @example
	# style_value(text_align: 'right', float: 'left')
	# => "text-align: right; float: left;"
	#
	# style_value(text_align: nil, float: 'left')
	# => "float: left;"
	#
	# style_value(width: [90, '%'], height: '50px')
	# => "width: 90%; height: 50px;"
	#
	# style_value(width: ['120px', 'px'])
	# => "width: 90px;"
	#
	# style_value(width: [nil, 'px'])
	# => nil
	#
	# @param declarations [Hash]
	# @return [String, nil]
	#
	def style_value(declarations)
	decls = []

	declarations.each do \|prop, value\|
	next if value.nil?

	if value.is_a? Array
	value, unit = value
	next if value.nil?
	value = value.to_s + unit unless value.end_with? unit
	end
	prop = prop.to_s.gsub('_', '-')
	decls << "#{prop}: #{value}"
	end

	decls.empty? ? nil : decls.join('; ') + ';'
	end

	def urlize(*segments)
	path = segments * '/'
	if path.start_with? '//'
	@_html5s_uri_scheme \|\|= document.attr('asset-uri-scheme', 'https')
	path = "#{@_html5s_uri_scheme}:#{path}" unless @_html5s_uri_scheme.empty?
	end
	normalize_web_path path
	end


	##
	# Gets the value of the specified attribute in this node.
	#
	# This is just an alias for +attr+ method with disabled _inherit_ to make it
	# more clear.
	#
	# @param name [String, Symbol] the name of the attribute to lookup.
	# @param default_val the value to return if the attribute is not found.
	# @return value of the attribute or +default_val+ if not found.
	#
	def local_attr(name, default_val = nil)
	attr(name, default_val, false)
	end

	##
	# Checks if the attribute is defined on this node, optionally performing
	# a comparison of its value if +expect_val+ is not nil.
	#
	# This is just an alias for +attr?+ method with disabled _inherit_ to make it
	# more clear.
	#
	# @param name [String, Symbol] the name of the attribute to lookup.
	# @param default_val the expected value of the attribute.
	# @return [Boolean] whether the attribute exists and, if +expect_val+ is
	# specified, whether the value of the attribute matches the +expect_val+.
	#
	def local_attr?(name, expect_val = nil)
	attr?(name, expect_val, false)
	end

	##
	# @param index [Integer] the footnote's index.
	# @return [String] footnote id to be used in a link.
	def footnote_id(index = local_attr(:index))
	"_footnote_#{index}"
	end

	##
	# @param index (see #footnote_id)
	# @return [String] footnoteref id to be used in a link.
	def footnoteref_id(index = local_attr(:index))
	"_footnoteref_#{index}"
	end

	def nowrap?
	'nowrap' if !document.attr?(:prewrap) \|\| option?('nowrap')
	end

	def print_item_content(item)
	wrap = item.blocks? && !item.blocks.all? { \|b\| b.is_a? ::Asciidoctor::List }
	[ (html_tag_if(wrap, :p) { item.text } if item.text?), item.content ].join
	end

	##
	# Returns corrected section level.
	#
	# @param sec [Asciidoctor::Section] the section node (default: self).
	# @return [Integer]
	#
	def section_level(sec = self)
	(sec.level == 0 && sec.special) ? 1 : sec.level
	end

	##
	# Returns the captioned section's title, optionally numbered.
	#
	# @param sec [Asciidoctor::Section] the section node (default: self).
	# @return [String]
	#
	def section_title(sec = self)
	sectnumlevels = document.attr(:sectnumlevels, DEFAULT_SECTNUMLEVELS).to_i

	if sec.numbered && !sec.caption && sec.level <= sectnumlevels
	[sec.sectnum, sec.captioned_title].join(' ')
	else
	sec.captioned_title
	end
	end

	##
	# @return [String] language of STEM block or inline node (tex or asciimath).
	def stem_lang
	value = (inline? ? type : style).to_s
	value == 'latexmath' ? 'tex' : value
	end

	def link_rel
	'noopener' if option?('noopener') \|\| attr(:window) == '_blank'
	end

	#--------------------------------------------------------
	# block_admonition
	#

	##
	# @return [Boolean] should be this admonition wrapped in aside element?
	def admonition_aside?
	%w[note tip].include? attr(:name)
	end

	##
	# @return [String, nil] WAI-ARIA role of this admonition.
	def admonition_aria
	case attr(:name)
	when 'note'
	'note' # https://www.w3.org/TR/wai-aria/roles#note
	when 'tip'
	'doc-tip' # https://www.w3.org/TR/dpub-aria-1.0/#doc-tip
	when 'caution', 'important', 'warning'
	'doc-notice' # https://www.w3.org/TR/dpub-aria-1.0/#doc-notice
	end
	end

	#--------------------------------------------------------
	# block_listing
	#

	##
	# @return [String] a canonical name of the source-highlighter to be used as
	# a style class.
	def highlighter
	@_html5s_highlighter \|\|=
	case (highlighter = document.attr('source-highlighter'))
	when 'coderay'; 'CodeRay'
	when 'highlight.js'; 'highlightjs'
	else highlighter
	end
	end

	##
	# Returns the callout list attached to this listing node, or +nil+ if none.
	#
	# Note: This variable is set by extension
	# {Asciidoctor::Html5s::AttachedColistTreeprocessor}.
	#
	# @return [Asciidoctor::List, nil]
	def callout_list
	@html5s_colist
	end

	def source_lang
	local_attr :language, false
	end

	#--------------------------------------------------------
	# block_open
	#

	##
	# Returns +true+ if an abstract block is allowed in this document type,
	# otherwise prints warning and returns +false+.
	def abstract_allowed?
	if result = (parent == document && document.doctype == 'book')
	log.warn 'asciidoctor: WARNING: abstract block cannot be used in a document
	without a title when doctype is book. Excluding block content.'
	end
	!result
	end

	##
	# Returns +true+ if a partintro block is allowed in this context, otherwise
	# prints warning and returns +false+.
	def partintro_allowed?
	if result = (level != 0 \|\| parent.context != :section \|\| document.doctype != 'book')
	log.warn "asciidoctor: ERROR: partintro block can only be used when doctype
	is book and it's a child of a book part. Excluding block content."
	end
	!result
	end

	#--------------------------------------------------------
	# block_table
	#

	def autowidth?
	option? :autowidth
	end

	def spread?
	if !autowidth? \|\| local_attr?('width')
	'spread' if attr? :tablepcwidth, 100
	end
	end

	#--------------------------------------------------------
	# block_video
	#

	# @return [Boolean] +true+ if the video should be embedded in an iframe.
	def video_iframe?
	['vimeo', 'youtube'].include? attr(:poster)
	end

	def video_uri
	case attr(:poster, '').to_sym
	when :vimeo
	params = {
	autoplay: (1 if option? 'autoplay'),
	loop: (1 if option? 'loop')
	}
	start_anchor = "#at=#{attr :start}" if attr? :start
	"//player.vimeo.com/video/#{attr :target}#{start_anchor}#{url_query params}"

	when :youtube
	video_id, list_id = attr(:target).split('/', 2)
	params = {
	rel: 0,
	start: (attr :start),
	end: (attr :end),
	list: (attr :list, list_id),
	autoplay: (1 if option? 'autoplay'),
	loop: (1 if option? 'loop'),
	controls: (0 if option? 'nocontrols')
	}
	"//www.youtube.com/embed/#{video_id}#{url_query params}"
	else
	anchor = [attr(:start), attr(:end)].join(',').chomp(',')
	anchor = '#t=' + anchor unless anchor.empty?
	media_uri "#{attr :target}#{anchor}"
	end
	end

	# Formats URL query parameters.
	def url_query(params)
	str = params.map { \|k, v\|
	next if v.nil? \|\| v.to_s.empty?
	[k, v] * '='
	}.compact.join('&')

	'?' + str unless str.empty?
	end

	#--------------------------------------------------------
	# document
	#

	##
	# @return [String, nil] the revision date in ISO 8601, or nil if not
	# available or in invalid format.
	def revdate_iso
	::Date.parse(revdate).iso8601 if defined? ::Date
	rescue ArgumentError
	nil
	end

	##
	# Returns HTML meta tag if the given +content+ is not +nil+.
	#
	# @param name [#to_s] the name for the metadata.
	# @param content [#to_s, nil] the value of the metadata, or +nil+.
	# @return [String, nil] the meta tag, or +nil+ if the +content+ is +nil+.
	#
	def html_meta_if(name, content)
	%(<meta name="#{name}" content="#{content}">) if content
	end

	# Returns formatted style/link and script tags for header.
	def styles_and_scripts
	scripts = []
	styles = []
	tags = []

	stylesheet = attr :stylesheet
	stylesdir = attr :stylesdir, ''
	default_style = ::Asciidoctor::DEFAULT_STYLESHEET_KEYS.include? stylesheet
	linkcss = attr?(:linkcss) \|\| safe >= ::Asciidoctor::SafeMode::SECURE
	ss = ::Asciidoctor::Stylesheets.instance

	if linkcss
	path = default_style ? ::Asciidoctor::DEFAULT_STYLESHEET_NAME : stylesheet
	styles << { href: [stylesdir, path] }
	elsif default_style
	styles << { text: ss.primary_stylesheet_data }
	else
	styles << { text: read_asset(normalize_system_path(stylesheet, stylesdir), true) }
	end

	if attr? :icons, 'font'
	if attr? 'iconfont-remote'
	styles << { href: attr('iconfont-cdn', FONT_AWESOME_URI) }
	else
	styles << { href: [stylesdir, "#{attr 'iconfont-name', 'font-awesome'}.css"] }
	end
	end

	if attr? 'stem'
	styles << { href: KATEX_CSS_URI }
	scripts << { src: KATEX_JS_URI }
	scripts << { text: KATEX_RENDER_CODE }
	end

	case attr 'source-highlighter'
	when 'coderay'
	if attr('coderay-css', 'class') == 'class'
	if linkcss
	styles << { href: [stylesdir, ss.coderay_stylesheet_name] }
	else
	styles << { text: ss.coderay_stylesheet_data }
	end
	end

	when 'highlightjs'
	hjs_base = attr :highlightjsdir, HIGHLIGHTJS_BASE_URI
	hjs_theme = attr 'highlightjs-theme', DEFAULT_HIGHLIGHTJS_THEME

	scripts << { src: [hjs_base, 'highlight.min.js'] }
	scripts << { text: 'hljs.initHighlightingOnLoad()' }
	styles << { href: [hjs_base, "styles/#{hjs_theme}.min.css"] }
	end

	styles.each do \|item\|
	if item.key?(:text)
	tags << html_tag(:style) { item[:text] }
	else
	tags << html_tag(:link, rel: 'stylesheet', href: urlize(*item[:href]))
	end
	end

	scripts.each do \|item\|
	if item.key? :text
	tags << html_tag(:script, type: item[:type]) { item[:text] }
	else
	tags << html_tag(:script, type: item[:type], src: urlize(*item[:src]))
	end
	end

	tags.join("\n")
	end

	#--------------------------------------------------------
	# inline_anchor
	#

	# @return [String] text of the xref anchor.
	def xref_text
	str =
	if text
	text
	elsif (path = local_attr :path)
	path
	elsif document.respond_to? :catalog # Asciidoctor >=1.5.6
	ref = document.catalog[:refs][attr :refid]
	if ref.kind_of? Asciidoctor::AbstractNode
	ref.xreftext((@_html5s_xrefstyle \|\|= document.attributes['xrefstyle']))
	end
	else # Asciidoctor < 1.5.6
	document.references[:ids][attr :refid \|\| target]
	end
	(str \|\| "[#{attr :refid}]").tr_s("\n", ' ')
	end

	# @return [String, nil] text of the bibref anchor, or +nil+ if not found.
	def bibref_text
	if document.respond_to? :catalog # Asciidoctor >=1.5.6
	# NOTE: Technically it should be `reftext`, but subs have already been applied to text.
	text
	else
	"[#{target}]"
	end
	end

	#--------------------------------------------------------
	# inline_image
	#

	# @return [Array] style classes for a Font Awesome icon.
	def icon_fa_classes
	[ "fa fa-#{target}",
	("fa-#{attr :size}" if attr? :size),
	("fa-rotate-#{attr :rotate}" if attr? :rotate),
	("fa-flip-#{attr :flip}" if attr? :flip)
	].compact
	end
	end