push.rb

class PushService < AbstractController::Base
  include AbstractController::Rendering
  self.view_paths = "app/views"

  def self.publish(recipient_ids, json)
    recipients = RecipentClass.where(:id.in recipient_ids).all
    FayePublisher.new(recipients, json).publish
    GcmPublisher.new(recipients, json).publish
  end

  # Create a new event to push to connected browsers and Android devices
  #
  # @param [Symbol] type of change :create, :destroy ...
  # @param [ActiveRecord] record which has been created or updated
  def initialize(type, record)
    Rails.logger.info "[PushService] #{type} #{record.inspect}"
    @type = type
    @record = record
  end

  def publish
    PushService.delay.publish @record.recipients.map(&:id), json
  end

  private

  def json
    @_json ||= {klass: @record.class.to_s, type: type_as_json, id: @record.id, record: record_as_json }
  end

  def record_as_json
    case @type
    when :destroy
      nil
    when :update
      @record.changes.each_with_object({}) { |(k, v), h| h[k] = v.last }
    when :touch
      {updated_at: @record.updated_at}
    else
      ActiveSupport::JSON.decode(render_template)
    end
  end

  def type_as_json
    @type == :touch ? :update : @type
  end

  def render_template
    render_to_string(:partial => @record, :locals => { :message => @record })
  end
end