How to trigger function after popToRoot() in ionic3?

I have to 3 page in the 3rd page i have to pass some parmaters and page is popToRoot() page is properly trigger to root but but function is not trigger i am using ionViewEnter, ionViewDidEnter but both are not working tell me anyone how to fix this page 2 is not used because we have to redirect to home page after change any field 2nd page we have to show categories?

Page1 - root page
ionViewDidEnter() {
Page 3-
	getCategoryViaField(fieldObject : any) {
		if( != "" && != undefined) {