[rules-users] Declared Types and Globals in different files with incremental KnowledgeAgent

[Davide Sottara]

Brecht, thanks for reporting this, but I don't think these are bugs.

1) In order to set the value of a global from a rule's RHS, you have to
do somehting like this

drools.getKnowledgeRuntime().setGlobal( "RULES_MATCHED", newValue );

The reason is that the rule's RHS sees a reference to the original
global... a local variable with the
same name initialized appropriately. Something like RULES_MATCHED = 0
will only change the local
reference, not modify the global.

2) The KnowledgeAgent supports declared types incrementally.. (Esteban
and I spent a lot of time to make
that work), but you have to set a flag in the KA's configuration:

KnowledgeAgentConfiguration aconf =
KnowledgeAgentFactory.newKnowledgeAgentConfiguration();
aconf.setProperty( "drools.agent.useKBaseClassLoaderForCompiling", true );

The "incremental" mode (newInstance=false) only ensures that the
existing KnowlegeBase is updated,
tue "useKBaseClassLoaderForCompiling" will ALSO make sure that, as the
new resources are compiled
by a KnowledgeBuilder, this is initialized with the KB's classloader,
which has the classes for the declared types.

3) I have proposed a fix for the issue you reported the other day...
actually two in one.
- 3a ) Runtime exceptions will be catched,
- 3b ) you **WILL NOT** be able to use primitive types with globals
anymore.. (which would result in a RTE anyway)

Hope this help
Best
Davide



On 09/20/2013 02:18 AM, De Rooms Brecht wrote:
> Dear Drools Users,
>
> I am building a network server for drools  since the existing
> drools-server did not meet my requirements.  Since I recently found a
> bug and find the people here very helpful I'll try to explain another
> issue I encountered in the hope that it improves drools 5.6 and 6.0.
> I noticed that declared types and globals don't seem to be found when
> you access them from a rule that was written in a different file. For
> the declared types I hacked around this issue by preprocessing the
> files and placing every declared type at the top of each file that
> needs it. For globals this is of course not possible.
>
> An example is shown below. File1 is loaded from the moment the agent
> starts up, then file2 is loaded.
> There is a difference when the knowledgeAgent detects the two files at
> once or one by one. In this case the KnowledgeAgent detects one file
> and then a few minutes later the other file and compiles them
> completely separately.
> The idea is to keep how many rules are matched of a certain type in a
> global.
>
>  *   FILE1: global_rules_matches.drl
>     ----------------------------------------------
>     package ellipsoidfacts
>
>     // declare
>     global Integer RULES_MATCHED;
>
>     // initialize global
>     rule "initRULESMATCHED"
>           salience 999
>           when
>   
>           then
>               RULES_MATCHED = 0;
>     end*
>
>  *   FILE2: testrule.drl
>     ----------------------------------------------
>     package ellipsoidfacts
>
>    rule "Gesture_lefthook"
>     when
>            
>         // ... any  precedent rules ...            
>
>     then
>         System.out.println("matched gesture:  lefthook"+ RULES_MATCHED);
>     end*
>
> In this particular case, my rule is not matched. I load these rules
> using a changeset xml, my knowledgeagent is set to incremental (but
> either doesnt work).
> The same happens when I declare types in FILE1 and use them in FILE2.
> When I write the type declaration in both files it works perfectly.
> Being the same package I assumed that these two scenarios should work.
> Am I doing something wrong or is the agent not supposed to work like
> this and should a package be in one file?
>
> Kind Regards,
> De Rooms Brecht
>
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20130920/e15fb29a/attachment.html