topic Re: RulesDeployer: What should happen if there are no rules? in Alfresco Archive

RulesDeployer: What should happen if there are no rules?

njames — Wed, 03 Oct 2012 20:20:23 GMT

Hi,I am trying to introduce Drools rules into my current processes. My process currently has a UserTask to manually approve a request. I am looking to add a BusinessRuleTask before it that would only allow the rules to circumvent the UserTask, effectively "auto-approving" the request.I would like to

Re: RulesDeployer: What should happen if there are no rules?

trademak — Thu, 04 Oct 2012 10:04:29 GMT

Hi,

So are you saying that you don't want to include a Drools rule file yet but do want to use a business rule task in the process definition?

Best regards,

Re: RulesDeployer: What should happen if there are no rules?

njames — Thu, 04 Oct 2012 22:21:44 GMT

That is correct. That way I can deploy my processes and business rules independently.
I can allow for having business rules that automate the approval process without mandating it. Making the business rule optional, if you will.
I'm just looking to start a discussion on this, and learn the advantages of Activiti throwing an exception if there are no rules.

Thanks,

Nick.

Re: RulesDeployer: What should happen if there are no rules?

trademak — Fri, 05 Oct 2012 06:42:32 GMT

Hi Nick,

Okay, the advantage of the current approach is that the versioning of the process definition is coupled to the rules that are deployed together.
If the rules would be deployed separately you would also have to point from the business rule task to a specific version / or the latest version of a set of rules.
This introduces quite some complexity.
If you would like to have a separate rules deployment it would make more sense to me to install Drools separately (maybe together with Guvnor) and connect remotely to it from a business rule task / service task. This remote functionality is not yet available in the business rule task but that should be easy to add.

Best regards,

Re: RulesDeployer: What should happen if there are no rules?

njames — Fri, 05 Oct 2012 17:59:55 GMT

Thanks for the ideas Tijs, I really appreciate it. The versioning would be done by using the latest version that is active (my business rules all have start and end dates). Hence the rule set could be updated on the fly by adding a new, active rule to the rule store.

I did think about using Guvnor to manage the rules, but it seemed easier to merely extend the existing deployment mechanism to find rules in other places.

I'm not sure that I want to use a "remote" drools engine because Activiti is the only process that would be using it. I would be paying the network latency price for no gain.

If I wanted to customize the stock implementation of BusinessRulesTaskActivityBehavior to get some of the rules from an alternate location, what would be the best way to do this? (Sorry for the newbie question).
I have experimented with the custom rules deployer, but it doesn't have direct access to the execution (I want to use one/some of the process variables to guide the rules discovery).

Thanks,

Nick.

Re: RulesDeployer: What should happen if there are no rules?

frederikherema1 — Tue, 09 Oct 2012 08:03:02 GMT

If you want to use the execution for determining what rules to use, it's indeed best to extend BusinessRulesTaskActivityBehavior or even start from a clean "org.activiti.engine.impl.bpmn.behavior.TaskActivityBehavior" and lookup the rules from within the execute-method and apply them.

Re: RulesDeployer: What should happen if there are no rules?

jasonwhite01 — Wed, 14 Nov 2012 08:34:48 GMT

Tijs - would you recommend the same remote-rules approach as a valid pattern when limited to not using business rules tasks by Alfresco?

I simply cannot believe there isn't a standard way to use a rules engine via Activiti when deploying process definitions within Alfresco but, seems terribly limited in alfresco….

Any help with either reference patterns and/or examples would help a ton.

Re: RulesDeployer: What should happen if there are no rules?

trademak — Sat, 17 Nov 2012 14:02:29 GMT

So, are you using Drools or something else as your rules engine?
The business rule task currently supports an embedded Drools engine.
But if there's need for remote Drools connectivity that wouldn't be too hard to add.

Best regards,