[rules-users] Does drools have any trigger?

[Marcus Ilgner]

2009/4/24 Lindy hagan <lindyhagan at gmail.com>:
> I was looking at  Blaze Advisor documentation it has  “when changed”
> operator that only fires when an attribute of an object changes. A business
> analyst might use it to watch for any important issue, such as a thermostat
> warning in a process plant or a particular stock reaching a certain price or
> volume.
>
> In similar way does Drools have this feature?
>
> Can any one correct if I am wrong: Rules can be updated by business users
> thru BRMS and Guvnor? (I did not get chance to go thru these)

Hi,

you can register your business objects (facts) as dynamic facts. They
will need to implement addPropertyChangeListener and related methods.
That way, as soon as a property that is used in a rule changes, the
rule will re-evaluate and fire if appropriate.
See section 2.5.4.7. of the docs for more information on this feature.

Best regards
Marcus