video_block.rb

class VideoBlock < ActiveRecord::Base

  belongs_to :content_block

  validates_presence_of :url
  validate :is_a_vimeo_link
  validates_length_of :title, maximum: 255

  before_save :set_video_id

  def vimeo_url?
    self.url.include?('vimeo.com')
  end

  private

  def is_a_vimeo_link
    errors.add(:url, 'must be from Vimeo') unless vimeo_url?
  end
  
  def set_video_id
    self.video_id = self.parse_vimeo_id if vimeo_url?
  end
  
  def parse_vimeo_id
    self.url.split("/").last
  end

  def as_json(options = {})
    options.reverse_merge! only: [:title, :caption, :url]
    super(options)
  end

end