[SOLVED] Tabs change events

Hello all
I have simple animated tabs:
https://framework7.io/docs/tabs.html#animated-tabs
but I need to catch tab changing event in JavaScript.
With other words, I need that each time tab is changed, JavaScript event is fired.
How to define that, please?
Thank you.

Read nolimits4web answer. Maybe it helps you.

Thanks but it does not work for me, I created JSfiddle here: https://jsfiddle.net/9ncztv5a/1/
What I’m doing wrong?

Please? Can anybody see where is the problem?

You need to put this logic in pageInit of that page https://jsfiddle.net/10gawnhy/

Just awesome. Thank you so much.