How to link external javascript file onclick of button

Question

The javascript file is there in Public/Scripts/filename.js. I have a template file in template/form.tmpl.html. Root folder contains Public and template folders

I wo

Answer 1

it seems like, it is impossible to call to a function in an external js file (test on chrome Version 63.0.3239.132). I tried it in many ways but it can't. I have to use the event listener.