title: Retrieve and integrate Webservices data into Grails Models
body: <p>I wanted to know how can I handle in a neat and modular way the follow situation, using Grails: </p>
  
  <p>I have some data in a local DB (Let's say Books, Authors, Reviews) and I need to enhance that data with information coming from one or more external WS. There can be different scenarios:</p>
  
  <ol>
  <li>Enhancing properties of an entity (e.g. I don't have the Book publishing year in the database, so I need to get it from a WS every time the user wants a Book)</li>
  <li>Federate the entities coming from the DB and from the WSs (e.g for each Book I have some reviews in local, but I can get more of them from external WSs)</li>
  </ol>
  
  <p>What it is the best way to handle this problem in Grails?</p>