What is purpose of swinging doors in old western saloons?

Question

What is purpose of swinging doors in old western saloons?

Answer 1

I've heard two thoughts on this.  One was that swinging doors closed themselves, so there was the convenience of not having to constantly shout for someone to close the d**n door.  Swinging doors allowed saloon patrons to see the hat and boots of whoever was approaching, giving fair warning!  Of course, those swinging saloon doors could all be a Hollywood fiction as well.