Class: Asciidoctor::Revealjs::SyntaxHighlighter::HighlightJsAdapter

Inherits:
SyntaxHighlighter::Base
  • Object
show all
Defined in:
lib/asciidoctor_revealjs/highlightjs.rb

Overview

Override the built-in highlight.js syntax highlighter

Constant Summary collapse

HIGHLIGHT_JS_VERSION =

REMIND: we cannot use Highlight.js 11+ because unescaped HTML support has been removed: https://github.com/highlightjs/highlight.js/issues/2889 We are using unescaped HTML in source blocks for callout.

'10.7.3'
HIGHLIGHT_PLUGIN_SOURCE =

this file was copied-pasted from https://raw.githubusercontent.com/hakimel/reveal.js/6.0.1/plugin/highlight/plugin.js (adapted from an ES module into a plain script, since it is inlined into the page) please note that the bundled highlight.js code was removed so we can use the latest version from cdnjs. Shared with the JavaScript implementation; see data/highlight-plugin.js.

File.read(File.join(__dir__, '..', '..', 'data', 'highlight-plugin.js')).freeze

Instance Method Summary collapse

Constructor Details

#initialize(name, backend = 'html5', opts = {}) ⇒ HighlightJsAdapter

Registering under the 'highlightjs'/'highlight.js' name overrides the built-in highlight.js syntax highlighter for every backend, not just revealjs - the SyntaxHighlighter registry has no notion of "per backend". Delegate to the built-in adapter for any other backend, so this converter's reveal.js-specific markup (data-line-numbers, data-noescape, the reveal.js highlight plugin docinfo) only shows up when actually converting to revealjs. See #489.



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# File 'lib/asciidoctor_revealjs/highlightjs.rb', line 21

def initialize(name, backend = 'html5', opts = {})
  super
  @name = @pre_class = 'highlightjs'
  @delegate = ::Asciidoctor::SyntaxHighlighter::HighlightJsAdapter.new(name, backend, opts) unless %w[revealjs reveal.js].include?(backend)
end

Instance Method Details

#_convert_highlight_to_revealjs(node) ⇒ Object

Convert between highlight notation formats In addition to Asciidoctor's linenum converter leveraging core's resolve_lines_to_highlight, we also support reveal.js step-by-step highlights. The steps are split using the | character For example, this method makes "1..3|6,7" into "1,2,3|6,7"



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# File 'lib/asciidoctor_revealjs/highlightjs.rb', line 32

def _convert_highlight_to_revealjs(node)
  node.attributes['highlight'].split('|').collect do |linenums|
    node.resolve_lines_to_highlight(node.content, linenums).join(',')
  end.join('|')
end

#docinfo(location, doc, opts) ⇒ Object 



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# File 'lib/asciidoctor_revealjs/highlightjs.rb', line 63

def docinfo(location, doc, opts)
  return @delegate.docinfo(location, doc, opts) if @delegate

  revealjsdir = (doc.attr :revealjsdir, 'reveal.js')
  theme_href = if doc.attr? 'highlightjs-theme'
                 doc.attr 'highlightjs-theme'
               else
                 "#{revealjsdir}/dist/plugin/highlight/monokai.css"
               end
  base_url = doc.attr 'highlightjsdir', %(#{opts[:cdn_base_url]}/highlight.js/#{HIGHLIGHT_JS_VERSION})
  %(<link rel="stylesheet" href="#{theme_href}"#{opts[:self_closing_tag_slash]}>
<script src="#{base_url}/highlight.min.js"></script>
#{if doc.attr?('highlightjs-languages')
    ((doc.attr 'highlightjs-languages').split ',').map do |lang|
      %(<script src="#{base_url}/languages/#{lang.lstrip}.min.js"></script>\n)
    end.join
  end}
<script>
hljs.configure({
  ignoreUnescapedHTML: true,
});
#{HIGHLIGHT_PLUGIN_SOURCE}
</script>)
end

#docinfo?(location) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/asciidoctor_revealjs/highlightjs.rb', line 57

def docinfo?(location)
  return @delegate.docinfo?(location) if @delegate

  location == :footer
end

#format(node, lang, opts) ⇒ Object 



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# File 'lib/asciidoctor_revealjs/highlightjs.rb', line 38

def format(node, lang, opts)
  return @delegate.format(node, lang, opts) if @delegate

  super(node, lang, (opts.merge transform: proc { |pre, code|
    code['class'] = %(language-#{lang || 'none'} hljs)
    code['data-noescape'] = true
    if (id = node.attr('data-id'))
      pre['data-id'] = id
    end
    code['data-trim'] = '' if node.option?('trim')

    if node.attributes.key?('highlight')
      code['data-line-numbers'] = _convert_highlight_to_revealjs(node)
    elsif node.attributes.key?('linenums')
      code['data-line-numbers'] = ''
    end
  }))
end