title: External value usage in Datamapper - WSO2 ESB
body: <p>A data format with:</p>
  
  <pre><code>Item: A
  Id: 001
  Price: 100.00
  </code></pre>
  
  <p>Should be converted into:</p>
  
  <pre><code>ItemName: A
  ItemId: 001
  Price: 100.00 * (1 + 0.1) ----&gt;(here the price should be calculated with commision)
  </code></pre>
  
  <p>Here commision is 0.1, should come from a static property (not constant but the commission may change daily) externally. How can I fix this using WSO2 ESB DataMapper?</p>