load javascript and css only when needed RAILS

Question

I am learning ruby on rails and javascript. Is there anyway to load js file only when needed by the railsapp? I tried to create simple application but when I check on the log, I realize it always load all the js, even the unneeded library.

I already searched it and found that it is using configuration to load a specific js only for specific pages.It's good, but I guess when we deal with a library that is used by many pages,, will make it hard to maintain. Could anyone give a good advice?

thank you

Answer 1

Take a look at requireJS : http://requirejs.org/

RequireJS is a JavaScript file and module loader. 
It is optimized for in-browser use, but it can be
used in other JavaScript environments, like Rhino and Node. Using a 
modular script loader like RequireJS will improve the speed and quality of your code.