title: XPages: optimise large forms when doing a partial refresh
body: <p>We have an XPages application, with a lot of forms. Everything is dynamic, meaning that the form content comes from one or more form definition document in Notes (one could say we built our own 'designer' environment): fields are dynamic, tabs, lists, etc... Now, as it happens, we have this enormous form with over a hundred fields, many of them are drop-down, with lots of options that are also dynamic.</p>
  
  <p>It works, but it's slow. When a drop-down field changes, it triggers a partial refresh with partial execute of the closest tab. But when we look at our logs, the partial execution affects the execution during the first phases. During rendering, our Java code recalculates the whole form and all the fields on all tabs. We already use a phase listener.</p>
  
  <p>@53.604: APPLY_REQUEST_VALUES, starts with going through all fields (~1s), then continues with the fields on one tab only. Great so far.</p>
  
  <p>@55.057: PROCESS_VALIDATIONS, tab only. Excellent.</p>
  
  <p>@55.338: UPDATE_MODEL_VALUES, tab only. Swell.</p>
  
  <p>@55.495: INVOKE_APPLICATION, tab only. Perfect.</p>
  
  <p>@55.651: RENDER_RESPONSE, the whole form is processed. </p>
  
  <p>@59.121: end of processing</p>
  
  <p>My question: <strong>Can we add some shortcuts to our code, so it can skip the evaluation of tabs and fields that don't change?</strong> </p>
  
  <p>For example, is it possible to find out using some built-in method or so whether XPages is doing a partial refresh, and of which element? </p>
  
  <p>Thanks for your assistance.</p>