ruby on rails 3 - yet another undefined method `model_name' for Project:Class -

i new rails , trying creating simple client youtube. using youtube_it gem retrieve videos in 1 of playlists , using code:

controller:

class playlistscontroller < applicationcontroller    def show     client = session[:client]     @playlist = client.playlist(params[:id])     @playlist.extend(baseplaylist)   end  end 

module extend youtube_it/playlist.class:

module baseplaylist   extend activemodel::naming   include activemodel::conversion    def model_name     'playlist'   end    def persisted?     false   end end 

playlists/show.html.erb:

<h1><%= @playlist.title %></h1>  <%= render 'form' %> 

playlists/_form.html.erb:

<%= form_for(@playlist) |f| %>      <% @playlist.videos.each |video| %>         <div class="field">           <%= f.check_box_tag video.title %>           <%= f.label video.title %>         </div>     <% end %>      <div class="actions">       <%= f.submit %>     </div> <% end %> 

what getting is:

undefined method `model_name' youtubeit::model::playlist:class 

what did above trying "wrap" playlist object doesn't work. idea?

while have defined module adds methods want, none of code in question shows how module added playlist class. i'm not familiar youtubeit gem can't sure how you'd that, if example wanted add module built-in string class you'd this:

class string     include baseplaylist end