Something added to Lotus Domino Designer (DD) in 8.5.1 was the ability to better illustrate our custom controls when laid out within an XPage (within Designer itself).

For example in 8.5 a tag cloud may look like this:


whereas in 8.5.1 we can now make it look like:


This is a simple example so big deal you may think, however with more complex custom controls (and XPages) and the fact that they are reusable so you want them to be as polished as possible its a great improvement. You can even include on screen instructions on how to reuse your custom control like I have in the following example:


So how do we do this? Well in a custom control we have a new setting "Design Definition" and this accepts XSP markup so we can make our custom control look/feel exactly how we wish:


For the simple example of the tag cloud, we just include an image (which is stored in the resources/images) and a panel which reuses composite data defined in the custom control and set within the current XPage (this.viewName for this example). You can even use an XPage/custom control to design your "design definition" and copy/paste into the markup box.