Elements for a related Model in a Form


I can't figure out how to do this:

I have a Post Model and it :has_and_belongs_to_many :tags. When I edit
a Post, I want to create checkboxes or a select field (with multiple
select choices), so I can add tags to a Post directly from its form.
Is there a way to achieve this nicely or do I have to create something
like just check_box_tags whithin a loop and process those back in the


I wanted to do something very similar and I modeled my application after this:



I've already implemented it in a very similar way, but that looks a
bit nicer. Thanks!