module UsersHelper

 def gravatar_for(user, option = {size:80})

   gravatar_id = Digest::MD5::hexdigest(user.email.downcase)
   gravatar_url = "https://secure.gravatar.com/avatar/#{gravatar_id}?s=#{option[:size]}"

   image_tag(gravatar_url, alt: user.name, class: "gravatar")
 end

end
