title: (Angular2) FormArray hide previous form as new form added
body: <p>I have a form array inside a formbuilder and i am dynamically changing forms, i.e. on click load data from application 1 etc.</p>
  
  <p>The issue i am having is that all the data loads in but the data in the <code>formarray</code> stays and just concats the old items with new.</p>
  
  <p>How do I make the <code>formarray</code> to only have the new array and hide the previous array. i am creating an array form using angular2.</p>
  
  <p><a href="https://plnkr.co/edit/ZLlOjsWfG0N6gcqvys1X?p=preview" rel="nofollow noreferrer">working plnkr</a> of my project</p>