How to run a method and output while a user types in an input box?

Question

I have an online tool, I have built with rails that takes a user input and output the result on the same page upon clicking a button. Upon clicking the button a complex code runs on the input and shows the result. How can I make the result appears while the user is typing the input, like real time capturing processing of the input. I am using Rails 5.1.4 and Ruby 2.4.2p198

Answer 1

You can bind keyup function and execute the handler function at real time when user types instead of when submit is clicked, I've created a simple fiddle, have a look

Demo https://jsfiddle.net/bLyovsj9/