ruby on rails 3.1 - What does require_self mean?

Question

In rails3.1 application.css we could see

/*
 *= require_self
 *= require_tree .
*/

I know that require_tree . is just telling the system to bundle together everything from the stylesheets folder into a single file.

But what does require_self tells?

Answer 1

From http://guides.rubyonrails.org/asset_pipeline.html:

/* ...
*= require_self
*= require_tree .
*/

"In this example require_self is used. This will put the CSS contained within the file (if any) at the top of any other CSS in this file unless require_self is specified after another require directive."