Extract video ID and get cover image URL from a YouTube embed code

youtube_video_id_and_cover.rb

# Method to get the cover image URL for a YouTube video by its ID
# There are several cover images avaiable for every video, you can specify which one you need through the type parameter
# For a list of possible cover types see http://stackoverflow.com/a/2068371/3463845
# The returned URL will be protocol-relative, so it should work on sides loaded through HTTP and HTTPS as well
def youtube_cover_for(id, type = :default)
  "//img.youtube.com/vi/#{id}/#{type}.jpg"
end

# Method to extract the video ID from a YouTube embed code
# This very simple regex works by exploiting the fact that the YouTube video IDs are always 11 characters long
def extract_youtube_id_from(embed_code)
  embed_code.match(/embed\/(.{11})/)[1]
end