This cool code snippet by Elior Shalev Tabeka gives user direct feedback upon submit button with built-in loading indicator. When you click on the animated go button, that changes its background colour upon hovering, will transform into loading indicator and then to a success button with a green background.
If you are having trouble with the pen, try the archived copy on GitHub
See the Pen
Button with Built-in Loading Indicator -JS and SCSS by Elior Tabeka (@eliortabeka)
on CodePen.