The first step is to turn on D2W debug mode in your app Properties file (if it isn't already).
er.extensions.ERXApplication.developmentMode = true
Advanced D2W Debugging
One of the most common problems to occur in a D2W application is that your rule that you've added just doesn't seem to be processed.
There is a very useful tool to find out what rules are being processed to compute values for D2W keys:
D2W rule tracing.
D2W Rule Tracing
One way to turn on rule tracing is in your app
log4j.logger.er.directtoweb.rules.ERD2WTraceRuleFiringEnabled = DEBUG
Then say you were trying to debug what rule, or set of rules, were being processed to determing the
class string applied to a Diva look component, you set:
Now when you launch your application and navigate to the page and/or component in question, you will see in the Console output, the D2W rules fired to determine the