We are using Drools 4.0.7 at present and looking to move to Drools 5.0. How
long is the old API expected to be supported? This will help us plan by when
we'll need to refactor our code to use the new APIs.
Depends what you mean. If you mean will each new version of drools
support the old api, probably not, we will deprecate over time, probably
after 5.2. We will however look to see if we can create a legacy jar and
move the old api there.
What about the rules in existing DRL files? I read in another post
are backward compatible.
Yes 100% backwards compatible
Will there be a huge learning curve in
understanding the new DRL syntax so that it can be used for upcoming rules?
Is there a problem in using the new DRL syntax with old Drools APIs?
no problem. Just be aware that any added method to core/compiler that
aren't in 4.0.x could disapear at any time. our commmitment to a legacy
jar is only for the methods available in 4.0.x