Ladda is a UI concept merging the loading indicator into the action invoked them. Here we package it for Asset Pipeline usage. The original source is from github.com/hakimel/Ladda where you can check out the instructions. And there is a demo page.
If there is a Gemfile, declare
gem "ladda-sprockets"
or
require "ladda-sprockets"
in proper situation in your application after $ gem install ladda-sprockets
Then in head of the major javascript file append
//= require "spin"
//= require "ladda"
Note you must declare //= require spin first. Spin is the dependency of Ladda.
If you have manual management of search paths of Sprockets::Environment, Ladda::Sprockets.path will return
the path of javascripts.
Stylesheets from Ladda can be loaded with
@import "ladda";
@import "ladda-theme";
Where ladda-theme is optional as documented in original README.