Printing your Ruby code – Benjamin Fleischer

18 November 2013
Follow @hazula

I was looking through Avdi Grimm’s GemLove library as an example of a RubyGems plugin and wanted to print the code. So, I wrote a script to higlight files, which I thought I’d share.

Notice that there is a gem contents [gem_name] command you can use to output the files included in a gem. Neato.

I may later evolve this into a ‘gem print’ command.

# Usage
# find path -type f | xargs ruby highlight.rb
# gem contents metric_fu | grep lib | xargs ruby highlight.rb

require 'coderay'
class Highlighter
  def initialize
    # import css classes from alpha style
    @css = CodeRay::Styles::Alpha::CSS_MAIN_STYLES << "\n" << CodeRay::Styles::Alpha::TOKEN_COLORS
  end

  def highlight_file(filename)
    text = File.binread(filename)
    highlight(text)
  end

  def highlight(text)
    CodeRay.scan(text, :ruby).div(css: :class, style: :alpha, line_numbers: :table, line_number_start: 0)
  end

  def highlight_files(filenames)
    filenames.map do |filename|
    "<br>#{filename}<br>" << highlight_file(filename)
    end.join("\n<br>")
  end

  def write_html(inner_html, output_filename)

    File.open(output_filename, 'w') do |output|
      output.write "<html><head><style>#{@css}</style></head><body>"
      output.write inner_html
      output.write "</body></html>"
    end

  end
end
if $0 == __FILE__
  hl = Highlighter.new
  inner_html = hl.highlight_files(ARGV.to_a)
  hl.write_html(inner_html, 'output.html')
end

And, as long as you’re here, I have also adapted a general Entity-Relationship Diagram generator that Erik Michaels-Ober wrote.

ruby 8