Class: MarkdownHighlightExtendedFilter

Inherits:
HTML::Pipeline::TextFilter
  • Object
show all
Defined in:
lib/markdown-highlight-extended-filter.rb

Overview

Stolen from github.com/imathis/octopress/blob/master/plugins/backtick_code_block.rb (MIT License)

Constant Summary collapse

AllOptions = 
/([^\s]+)\s+(.+?)\s+(https?:\/\/\S+|\/\S+)\s*(.+)?/i
LangCaption = 
/([^\s]+)\s*(.+)?/i

Instance Method Summary collapse

Instance Method Details

#call ⇒ Object 



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# File 'lib/markdown-highlight-extended-filter.rb', line 10

def call
  format_syntax(@text)
end

#format_syntax(text) ⇒ Object 



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# File 'lib/markdown-highlight-extended-filter.rb', line 14

def format_syntax(text)
  text.gsub(/^`{3} *([^\n]+)?\n(.+?)\n`{3}/m) do
    options = $1 || ''
    str = $2

    if options =~ AllOptions
      lang = $1
      caption = "<figcaption><span>#{$2}</span><a href='#{$3}'>#{$4 || 'link'}</a></figcaption>"
    elsif options =~ LangCaption
      lang = $1
      caption = "<figcaption><span>#{$2}</span></figcaption>"
    end

    if str.match(/\A( {4}|\t)/)
      str = str.gsub(/^( {4}|\t)/, '')
    end
    if lang.nil? || lang == 'plain'
      code = highlight_code(str.gsub('<','&lt;').gsub('>','&gt;'), "plain")
      "<figure class='code'>#{caption}#{code}</figure>"
    else
      if lang.include? "-raw"
        raw = "``` #{options.sub('-raw', '')}\n"
        raw += str
        raw += "\n```\n"
      else
        code = highlight_code(str, lang)
        "<figure class='code'>#{caption}#{code}</figure>"
      end
    end
  end
end

#highlight_code(code, lang) ⇒ Object 



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# File 'lib/markdown-highlight-extended-filter.rb', line 46

def highlight_code(code, lang)
  if lexer = lexer_for(lang, code)
    # XXX: Rouge wrapper `<pre css_class><code>` is different from
    # what pygments generates `<div css_class><pre>`.
    # To keep compatibility, we don't use Rouge's warp, and wrap it manually.
    html = Rouge::Formatters::HTML.format(lexer.lex(code), :wrap => false)
    %Q{<div class="highlight highlight-#{lexer.tag}"><pre>#{html}\n</pre></div>}
  else
    "<pre>#{code}</pre>"
  end
end

#lexer_for(lang, code) ⇒ Object 



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# File 'lib/markdown-highlight-extended-filter.rb', line 58

def lexer_for(lang, code)
  Rouge::Lexer.find(lang)
end