Class: Jekyll::HighlightBlock

Inherits:
Liquid::Block
  • Object
show all
Includes:
Liquid::StandardFilters
Defined in:
lib/jekyll/tags/highlight.rb

Overview

Highlights code using Pygments.rb

The syntax for the tag is “highlight <lang> [<opt>, …]”.

See ‘pygmentize -L lexers` for the list of available languages.

Options:

cssclass - CSS class for the wrapping DIV tag (default: ‘highlight’) classprefix - string to prepend to all generated CSS class names

(default: '')

hl_lines - list of lines to be highlighted (default: none) linenos - show line numbers in “inline” style; when set to “table”

render line numbers in a separate table column
(default: false)

linenostart - initial line number (default: 1) lineanchors - a string prefix that triggers wrapping each output line

in an anchor tag with name in "<prefix>-<line>" format
(default: none)

anchorlinenos - in combination with ‘linenos=table` and `lineanchors`, turn

line numbers into links to individual lines (default: false)

Examples

{% highlight ruby %}
... ruby code ...
{% endhighlight %}

# Show line numbers:
{% highlight js linenos linenostart=5 %}

# Highlight lines 1,3,5:
{% highlight css hl_lines=1_3_5 %}

Constant Summary collapse

SYNTAX =

The regular expression syntax checker. Start with the language specifier. Follow that by zero or more space separated options that take one of two forms:

  1. name

  2. name=value

/^([a-zA-Z0-9.+#-]+)((\s+\w+(=[\w-]+)?)*)$/

Instance Method Summary collapse

Constructor Details

#initialize(tag_name, markup, tokens) ⇒ HighlightBlock

Returns a new instance of HighlightBlock.



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# File 'lib/jekyll/tags/highlight.rb', line 48

def initialize(tag_name, markup, tokens)
  super
  @options = { :encoding => 'utf-8' }
  if markup.strip =~ SYNTAX
    @lang = $1
    $2.to_s.split.inject(@options) do |opts, opt|
      process_option(*opt.split('=', 2)) do |key, value|
        opts[key] = value
      end
      opts
    end
  else
    raise SyntaxError.new("Syntax Error in 'highlight' - Valid syntax: highlight <lang> [linenos]")
  end
end

Instance Method Details

#add_code_tags(code, lang) ⇒ Object 



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# File 'lib/jekyll/tags/highlight.rb', line 108

def add_code_tags(code, lang)
  # Add nested <code> tags to code blocks
  code = code.sub(/<pre>/,'<pre><code class="' + lang + '">')
  code = code.sub(/<\/pre>/,"</code></pre>")
end

#process_option(key, value = nil) {|key, value| ... } ⇒ Object

Validates option for Pygments.

Yields key, value if the option has value.

Raises ArgumentError for unsupported options.

Yields:

  • (key, value) 


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# File 'lib/jekyll/tags/highlight.rb', line 69

def process_option(key, value = nil)
  case key
  when 'linenos'       then value ||= 'inline'
  when 'hl_lines'      then value = value.to_s.split(/\D/)
  when 'anchorlinenos' then value ||= true
  when 'lineanchors', 'linenostart', 'cssclass', 'classprefix'
    # these have a string value
  else
    raise ArgumentError, "unsupported Pygments option: #{key}"
  end

  yield key, value unless value.nil?
end

#render(context) ⇒ Object 



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# File 'lib/jekyll/tags/highlight.rb', line 83

def render(context)
  if context.registers[:site].pygments
    render_pygments(context, super)
  else
    render_codehighlighter(context, super)
  end
end

#render_codehighlighter(context, code) ⇒ Object 



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# File 'lib/jekyll/tags/highlight.rb', line 99

def render_codehighlighter(context, code)
  #The div is required because RDiscount blows ass
  <<-HTML
<div>
  <pre><code class='#{@lang}'>#{h(code).strip}</code></pre>
</div>
  HTML
end

#render_pygments(context, code) ⇒ Object 



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# File 'lib/jekyll/tags/highlight.rb', line 91

def render_pygments(context, code)
  pretty = Pygments.highlight code, :lexer => @lang, :options => @options
  output = add_code_tags(pretty, @lang)
  output = context["pygments_prefix"] + output if context["pygments_prefix"]
  output = output + context["pygments_suffix"] if context["pygments_suffix"]
  output
end