friend_label.html

<!-- an example "friend label" -->
<div class='friend_container'>
  <div class='friend_image'>
    <div class='image'></div>
  </div>
  <div class='friend_name'>@adorableLizard</div>
  <div class='friend_info'>Twitter User</div>
</div>

friends_schema.json

[
  {
    :is_dm => true,
    :kind => "Twitter User",
    :label => "<div class='friend_container'><div class='friend_image'><div class='image'></div></div><div class='friend_name'>@adorableLizard</div><div class='friend_info'>Twitter User</div></div>",
    :value => "@adorableLizard"
  }
]

ui_controller.rb

class UiController < ApplicationController
  def fb_autocomplete_friends
    # phrase the user is searching for
    term = params[:term]
    
    raise "Term must be provided." unless term
    
    # a sample list of friends
    friends = [
      { :label => nil, :kind => "Facebook User", :value => "Karina Sasse" },
      { :label => nil, :kind => "Facebook User", :value => "Nannie Nell" },
      { :label => nil, :kind => "Facebook User", :value => "Tabatha Liss" },
      { :label => nil, :kind => "Facebook User", :value => "Althea Deeds" },
      { :label => nil, :kind => "Facebook User", :value => "Eve Howton" },
      { :label => nil, :kind => "Facebook User", :value => "Amie Rieves" },
      { :label => nil, :kind => "Facebook User", :value => "Lonnie Marrone" },
      { :label => nil, :kind => "Facebook User", :value => "Nelson Fitzhenry" },
      { :label => nil, :kind => "Facebook User", :value => "Max Pawlowicz" },
      { :label => nil, :kind => "Facebook User", :value => "Tameka Rutten" },
      { :label => nil, :kind => "Twitter User", :value => "@adorableLizard" },
      { :label => nil, :kind => "Twitter User", :value => "@bunny_cheese" },
      { :label => nil, :kind => "Twitter User", :value => "@combatIron" },
      { :label => nil, :kind => "Twitter User", :value => "@singinggurl" },
      { :label => nil, :kind => "Twitter User", :value => "@MoonDespair" },
      { :label => nil, :kind => "Twitter User", :value => "@EvilLover" },
      { :label => nil, :kind => "Twitter User", :value => "@LovelyPrincess" },
      { :label => nil, :kind => "Twitter User", :value => "@Grimlyadorable" },
      { :label => nil, :kind => "Twitter User", :value => "@JoyfulIronOptimist" },
      { :label => nil, :kind => "Twitter User", :value => "@WeaselSpring" }
    ]
    # a list of matching friends, and a list of friends with their
    # labels rendered
    found_friends, rendered_friends = [], []
    
    # a version of term which has "dm " stripped off the front if
    # present
    t = nil
    
    # if the user is attempting a direct message, this will be true
    is_dm = false
    
    # set is_dm and t, if necessary
    if(term.match(/^dm\s+\@/))
      is_dm = true
      
      t = term.gsub!(/^dm\s+/, '') 
    end
    
    # filter for found friends, and render the dynamic fields for them
    # using the "fb_autocomplete_friend" helper as contents of label
    if(t != "@" && t.length > 0)
      found_friends = friends.find_all do |f|
        f[:value].downcase.match(/^#{t}/i)
      end
      
      rendered_friends = found_friends.map do |f|
        f[:is_dm] = is_dm
        f[:label] = render_to_string :partial => 'fb_autocomplete_friend',
          :locals => { :name => f[:value], :term => term, :kind => f[:kind] }
        f
      end
    end
    
    render :json => rendered_friends
  end
end