Create 'poll_question_answer_videos' table and model

app/models/poll/question/answer.rb

@@ -1,5 +1,6 @@
 class Poll::Question::Answer < ActiveRecord::Base
   belongs_to :question, class_name: 'Poll::Question', foreign_key: 'question_id'
+  has_many :videos, class_name: 'Poll::Question::Answer::Video'
 
   validates :title, presence: true
 

app/models/poll/question/answer/video.rb

@@ -0,0 +1,16 @@
+class Poll::Question::Answer::Video < ActiveRecord::Base
+  belongs_to :answer, class_name: 'Poll::Question::Answer', foreign_key: 'answer_id'
+
+  VIMEO_REGEX = /vimeo.*(staffpicks\/|channels\/|videos\/|video\/|\/)([^#\&\?]*).*/
+  YOUTUBE_REGEX = /youtu.*(be\/|v\/|u\/\w\/|embed\/|watch\?v=|\&v=)([^#\&\?]*).*/
+
+  validates :title, presence: true
+  validate :valid_url?
+
+  def valid_url?
+    return if url.blank?
+    return if url.match(VIMEO_REGEX)
+    return if url.match(YOUTUBE_REGEX)
+    errors.add(:url, :invalid)
+  end
+end