Use Opentok API in Rails

Opentok_rails.rb

# 1. plugin
# Download the ruby SDK code, and copy to the plugin directory. 
${RAILS_ROOT}/vendor/plugins/opentok

# You may need to create an "init.rb" file in the opentok plugin directory, 
# and insert the following line.
require 'opentok'


# 2. database
# I have a set of "topics", where each topic page contains an opentok video session. 
# So, I created a database table to store the opentok session ID for each topic. 
# Below is the code for db migration.

class CreateOpentokSessions < ActiveRecord::Migration
  def self.up
    create_table :opentok_sessions do |t|
      t.integer :topic_id
      t.string  :session_id, :default => "", :null => false
    end
    add_index :opentok_sessions, :topic_id
  end

  def self.down
    drop_table :opentok_sessions
  end
end


# 3. model
# Create the corresponding model for opentok session and the relationship with topics.

# opentok_session.rb
class OpentokSession < ActiveRecord::Base
  belongs_to :topic, :class_name => 'Topic'
end

# topic.rb
class Topic < ActiveRecord::Base
...
  has_one :opentok_session, :class_name => "OpentokSession", :foreign_key => "topic_id", :dependent => :destroy
...
end



# 4. controller
# In the topics controller, retrieve the opentok session ID or create a new one 
# if it does not exist yet. Then pass the session ID and generated token to the view.

  # function to initialize the opentok object
  def config_opentok
    if @opentok.nil?
      @opentok = OpenTok::OpenTokSDK.new YOUR_OPENTOK_API_KEY, "YOUR_OPENTOK_API_SECRET"
      @opentok.api_url = 'https://staging.tokbox.com/hl'
    end
  end

  def show
    ...
    config_opentok
    tok_session = OpentokSession.find(:first, :conditions => {:topic_id => @topic})
    if tok_session.nil?
      id = @opentok.create_session '127.0.0.1'
      tok_session = OpentokSession.create(:topic_id => @topic.id, :session_id => id.to_s)
      tok_session.save
    end
    @tok_session_id = tok_session.session_id
    @tok_token = @opentok.generate_token :session_id => @tok_session_id
    ...
  end


# 5. view
# 
# In the topic view, insert the javascript and show the opentok video panel. 
# This is basically the same as in the opentok tutorial.

  <script type="text/javascript" charset="utf-8">
      var apiKey = YOUR_OPENTOK_API_KEY;
      var sessionId = "<%= @tok_session_id %>";
      var token = "<%= @tok_token %>";
  </script>
  <script src="http://192.168.1.4:3000/javascripts/tokbox.js" type="text/javascript"></script>
  <div class="tokbox_frame" id="tokbox_frame">
      <div id="links">
        <a href="#" onclick="javascript:connect();" id="connectLink">Join video</a>
        <a href="#" onclick="javascript:publish();" id="publishLink">Publish video</a>
        <a href="#" onclick="javascript:unpublish();" id="unpublishLink">Unpublish video</a>
      </div>
      <div id="publisherDiv" class="publisherContainer"></div>
      <div id="subscriberBar"></div>
  </div>