gistfile1.rb

# Helper that adds inline CSS styles to the tags you want from an html string.
# Examples:
#   add_styles("<p>Ohi</p>", :p => 'color:red')       # => '<p style="color:red">Ohi</p>'
#   add_styles("<p>Ohi</p>", :p => {:color => 'red'}) # => '<p style="color:red">Ohi</p>'
def add_styles(html, tags)
  html = html.dup
  tags.each do |tag, style|
    style = style.map{|k,v| "#{k}:#{v}"}.join(';') unless style.is_a?(String)
    html.gsub! /<(#{tag}.*?)(?: style="(.*?)")?(.*?)>/,
      "<\\1 style=\"#{style};\\2\"\\3>"
  end
  html
end