method
auto_link
auto_link(text, link = :all, href_options = {}, &block)
public
Turns all urls and email addresses into clickable links. The link parameter can limit what should be linked. Options are :all (default), :email_addresses, and :urls.
Example:
auto_link("Go to http://www.rubyonrails.com and say hello to david@loudthinking.com") => Go to <a href="http://www.rubyonrails.com">http://www.rubyonrails.com</a> and say hello to <a href="mailto:david@loudthinking.com">david@loudthinking.com</a>
If a block is given, each url and email address is yielded and the result is used as the link text. Example:
auto_link(post.body, :all, :target => '_blank') do |text| truncate(text, 15) end

