UsersHelper.rb

module UsersHelper

  #Returns the Gravatar for the given user.
  def gravatar_for(user, options = { size: 50 })
    gravatar_id = Digest::MD5::hexdigest(user.email.downcase)
    size = options[:size]
    gravatar_url = "https://secure.gravatar.com/avatar/#{gravatar_id}?s=#{size}"
    image_tag(gravatar_url, alt: user.email, class: "img-responsive")
  end

  def show_rating_in_stars(rating)
    show_n_stars(from_rounded(rating)).html_safe
  end
  
  private
  def from_rounded(rating)
    rounded = (rating * 2).round / 2.0
    rounded.prettify.to_i
  end

  def show_n_stars(n)
    n.times.reduce("") {|images, time| images += image_tag('star_on.png') }
  end
end