title: Add a new attribute to existing product type - SAP Hybris e-Commerce
body: <p>I am trying to add a new attribute called 'url_key' to the existing product type created by Hybris on initialization just for learning purposes.</p>
  
  <p>I had created my item type in my extension like this:</p>
  
  <pre><code>&lt;itemtype code="UrlKeyProduct" extends="Product" generate="false"&gt;
      &lt;attributes&gt;
          &lt;attribute autocreate="true" qualifier="url_key" type="java.lang.String"&gt;
              &lt;persistence type="property"/&gt;
              &lt;modifiers read="true" write="true" search="true" initial="true" optional="true" unique="true"/&gt;
          &lt;/attribute&gt;
      &lt;/attributes&gt;
  &lt;/itemtype&gt;
  </code></pre>
  
  <p>Compiled, and now I see a UrlKeyProductModel.java and a GeneratedUrlKeyProductModel.java... but what to do now to have this new attribute available on the product cockpit when creating/updating a product and also in my OCC response through REST?</p>
  
  <p>I saw references to several xml files like editorArea, but I don't know if these files already exists or do I have to create them or where.</p>
  
  <p>Any thanks appreciated.</p>