title: Ionic event to identify user came from navCtrl.pop()
body: <p>I have three pages named as page1,page2 and page3</p>
  
  <p>and their navigation will be page1->page2->page3 </p>
  
  <p>How we can identify on page2 that user came on this page via NavController Push or Pop function.</p>
  
  <p>I just want to trigger a function on page2 only if they perform some action on page3 and redirected to page2 via navCtrl.pop() function. </p>
  
  <p>I know i can put condition in ionViewWillEnter for last view name from nav stack, Because it will be fired everytime user be on page2. But If there is any other alternate or good way to do this. Please let me know </p>
  
  <p>Thanks </p>