How to retain view\page state in ionic 2?

Hi,
I have an app in which I have couple of pages. On click of a button in 1st page, I navigate to 2nd page and on ionViewDidLoad, I am calling data service and rendering the data in a list.
Next, when I navigate back by clicking back button on top, I go to 1st page. Now again, if i click on the button in 1st page, I navigate to 2nd page. However, in this case, service call is made again, which means ionVIewDidLoad is triggered again (which is what i want to avoid)

How can I retain the previous state of the 2nd view? I am not using setRoot. I am using push and pop of the navigator.