R.I.P. Red Boxes

WARNING: This blog entry was imported from my old blog on blogs.sun.com (which used different blogging software), so formatting and links may not be correct.

One of the really nice things about Creator and JSF is that we're able to provide WYSIWYG editing of components. We do this by actually running the components' renderers at designtime. This does however have one problem: What if the component renderers aren't happy? Lots of things can go wrong. For example, let's say you have a databound JSF table. If you kill the database connection, the component renderer will abort with a SQLException. Incorrect expression language bindings, missing converters and a whole host of other potential problems have similar issues. How do we handle this in the IDE? In Creator 1.0, we had the "Red Boxes" scheme, as shown in the first screenshot on the right. In the designer, components which aborted during rendering would be shown partially (as much as possible depending on how far along the renderer got before dying), but all the markup would be changed to have a red background. That way you could sort of see the component if it had rendered enough before giving up. This is better than not showing the component at all, since (1) it makes it really obvious that there is a problem, and (2) it makes the troubled component easy to select so you can inspect the property sheet and try to fix the problem. We also opened the Output window with an error message trying to explain what had happened, and what to do about it. In Creator 2 this behavior has changed. Instead of the red boxes, you first get an error screen (similar to the one you get if you introduce parsing errors in the JSP, or syntax errors in the Java file). This error screen includes portions of the stacktrace, which in many cases might reveal what the problem is (don't forget to look for a cascaded exception1) You can also click through to the design view, and now you'll see the component. However, rather than an ugly red box you'll see a small error icon in the component's place along with an error message associated with the render problem. It should also be much better about not repeating the error screen until you've resolved the problem and encounter a new problem (although there was a bug in this area fixed shortly after EA).