title: ag-grid in angular5 row inline edit
body: <p>I want to know the best way I can give user inline edit in ag-grid on button click.</p>
  
  <p>see the image below.
  <a href="https://i.stack.imgur.com/19VJ4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/19VJ4.png" alt="enter image description here"></a></p>
  
  <p>As per my requirement, if user clicks on edit icon, then ag-grid row goes in fullrow edit mode (able to do from documentation provided onag-grid.com) and at the same time, icons in 'Action' column changes to save and cancel icons. So, want to know how this can be done in Angular5. I need idea of dynamically changing this last column.</p>