I hunted around for a while to find this solution and did not succeed.
What I’m wondering is whether there is a way, through a toggle or option field in a collection, to add a class to an element on the post template.
For instance, a toggle in a collection item for combo class adds like “Large, Medium, Small, Tall, Short, Wide, Narrow, Border, No-Border” which targets one specific class of an image object as it appears on the post template. So, if the client wants the image to have a border, they can just add it right through the collection editor with a toggle.
I realize this can get out of control quickly, and I also realize there are other ways of solving this problem, but I’m specifically interested in the underlying ability to add a combo class to an element on the post page through a selection made in the collection db.