Rails nested forms STI autosave

Rails nested forms STI autosave

I have one class "Section" and many other classes "SectionText",
"SectionQuote" etc using STI, elements that compound a Post. (Post
has_many sections). I'm using a autosave custom method via Ajax for build
new sections nested on Post, but I think this isn't a better choice!
I need autosave the sections, when user click on another component. What's
the better way to solve this? Thanks...