Event page to get ajax data calls only first time

Hi, i´m trying to use page events to make a few ajax calls only the first time i go to a page. I´m using the init event, but when i navigate to another page and return to the first one, the calls are made again.
I’ve tried reinit event, but i’m not able to catch this event anyways.
Any solutions?

Did you try with stackPages.

I dont know how that works… Could you please explain it a little bit more?