title: SmartGWT FilterBuilder as DynamicForm?
body: <p>I have a rather large implementation of a SmartGWT <code>FilterBuilder</code>, pretty similar to the <a href="http://www.smartclient.com/smartgwt/showcase/#grid_big_filter" rel="nofollow">Big Filter example in the SmartGWT showcase</a>.  The <code>FilterBuilder</code> uses a <a href="http://www.smartclient.com/smartgwt/javadoc/com/smartgwt/client/data/RestDataSource.html" rel="nofollow"><code>RestDataSource</code></a> underneath to create it's fields via <code>FormItem</code>s with operators and available values, some of which are pulled from the server and other's that are created by client-side data (i.e. a <code>ComboBoxItem</code> with options from a <code>ValueMap</code>).  I currently make requests to the server based on the underlying criteria and that works just fine.  Now, I want to prevent my query button from performing it's <code>onclick</code> handler when the values in the FormItems are invalid.  I've been able to successfully add Validator's to some of the <code>FormItem</code>s and <code>DataSourceField</code>s, and I can see in the GWT debugger that I am getting "invalid" returned from <code>CustomValidator</code>'s condition, yet, when I call <code>filterBuilder.validate()</code> I always get back <code>true</code> (even with clearly invalid values in fields).</p>
  
  <p>What gives?  How can I validate on a <code>FilterBuilder</code> ?</p>