title: jquery datatables - get columns from json
body: <p>In jquery Datatables is it possible to define columns with a server-side script?
  I need something like this 
  <img src="https://i.stack.imgur.com/eOnmc.png" alt="enter image description here"></p>
  
  <p>The columns with dates have to be loaded from server.
  Then number of columns can vary.</p>