Convert old-style blurt content to new

content.rake

namespace :content do
  
  desc "Convert old-style code blocks to new format"
  task :convert_code => :environment do
    require 'hpricot'
    
    Post.all.each do |post|
      doc = Hpricot(post.body)
      (doc/'code').each do |node|
        header = node['lang'] ? "    #lang:#{node['lang']}\n" : ''
        
        lines = node.inner_html.sub(/^\n+/, '').split("\n")
        
        matches = lines.first.match(/^( +)/)
        indent = matches ? (' ' * matches[1].length) : ''
        
        block = lines.map do |line|
          line.sub(/^#{indent}/, '    ')
        end.join("\n")
        
        node.swap "#{header}#{block}"
      end
      
      post.body = doc.to_s
      post.send(:update_without_timestamps)
      
    end
  end
end