Re: [rules-users] Condition syntax to access Map

On 28/07/2011 08:26, bolsover wrote: I'm not sure it's supported in our parser, but I think we should do it - either add support for it, or make it implement to the "." accessor. MVEL supports null safe navigation, which means it'll return false if a null value is returned from an accessor. http://mvel.codehaus.org/MVEL+2.0+Property+Navigation "Sometimes you have property expressions which may contain a null element, requiring you to create a null-check. You can simplify this by using the null-safe operator: user.?manager.name This is functionally equivalent to writing: if (user.manager !=null) {return user.manager.name; }else {return null; }" I doubt there is a time when someone wants a nullpointer to happen. So maybe we should build this in as default into expressions. I guess the only time we shouldn't is if people know it will enver be null and don't want the small overad for the null check. What do people think? Mark