+
+
+ # Abstract definition. Each subclass of Website
+ # should support it on its own.
+ def self.owns_url?(url)
+ raise NotImplementedError
+ end
+
+
+ # Same here. Abstract.
+ def get_video_url()
+ raise NotImplementedError
+ end
+
+
+ # The website class should be responsible for determining the
+ # video's filename. By default, we can take the last component
+ # of the video URL, but in some cases, subclasses will want
+ # to override this behavior.
+ def get_video_filename()
+ # Use whatever comes after the final front slash.
+ return get_video_url().split('/').pop()
+ end
+