Have you looked into aspect oriented programming? You should be able accomplish your objectives using it. One example open source effort is the Spring framework. Good luck. - andy
John MccLain <[EMAIL PROTECTED]> wrote: We have a fairly large client/server app that we converted to a java webapp. The original app was in powerbuilder. there were 2 types of rules applied to field rendering: 1) any rule that could be handled when the screen loaded was handled via screen level events, e.g., if a screen had fields with default values, or hidden fields under certain conditions, then these would be applied at screen entry via an onchange event for the screen 2) computed fields were handled via onChange events on the field, e.g., if field x changes, change field y The 'field rules' could be any valid powerscript expression What we have done is mimicked this in java. we process the same way as above, except we dynamically convert (very painfully) the powerscript into java syntax, then run the rules as above, by passing the converted rules to an embedded java interpreter (BeanShell) The problem is if you have sophisticated rules, or rules which affect many different fields, e.g., if field x changes, change field y, but if field y changes, change field z, etc... This becomes very slow - up to 15 seconds for a screen to render or change completely. Not to mention the complexity of the rules management. Is there a better way??? John McClain Senior Software Engineer TCS Healthcare [EMAIL PROTECTED] (530)886-1700x235 "Skepticism is the first step toward truth" --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com