title: How to implement substring function?
body: <p>I have used  substring function in composer and the output should be the number extracted from the given value. Here the condition reaches to false branch.
  By following the doc I have used below steps but I am not getting the output. It will be very helpful if somebody provides the solution.
  <a href="https://i.stack.imgur.com/nCorJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nCorJ.png" alt="enter image description here" /></a></p>
  <p>I have used &quot;= substring('${dialog.Str}', 4, 7) &quot; as well.</p>
  <p>I want 1234 only intger part to be stored in a property.</p>
  <p>Thanks...</p>