That’s actually my ticket, and I’ve been hoping to get it resolved for awhile now.  I’ve posted to this mailing list as well as the actual ticket but haven’t heard responses from anyone.

 

I’ve recently done more research into the issue, and have some updated information that needs to be attached to the ticket (I’ll try to get it in shortly) but what it boils down to is a collision of two problems…

 

Problem 1: DSL and DSLR need to be in the same folder, but if you don’t explicitly list the resources for each item in the changeset, you can’t define an independent resource type.    This is kind of silly and in my mind defeats the benefits of the change-set.  The benefit in my mind of a change set is being able to point it at a folder and have it scan for new rule additions as well as changes.

 

Problem 2: Internally the identified resources in the change set are held in a hashmap.  Since there’s no ordering to a hashmap, when they’re pulled out and added to the knowledgebuilder they could be added in any order.  In order for a DSL and DSLR to work, they have to be added to the KnowledgeBuilder in the proper order (DSL first then DSLR).  It does not matter what order you list them in the change set, the rebuild code in the KnowledgeAgent framework does not enforce any concept of ordering or priority to resource types.

 

The documentation (since 5.0.1) has suggested that at some point they plan to have “autodetection” of file types which would solve for problem #1, but problem #2 would remain without some priority given to how the KnowledgeBuilder is being instructed to construct rule sets.  This problem is present even in the latest 5.1 milestone.

 

Unfortunately this has driven us to choose between having a DSL or having hot deployment of rules (we’ve chosen the later)

 

Macon

 


From: rules-users-bounces@lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Steve Ronderos
Sent: Tuesday, January 26, 2010 2:58 PM
To: Rules Users List
Subject: Re: [rules-users] KnowledgeAgent doesn't load dsl files and dslr file from a change-set correctly

 


Pritham,

I've experienced this issue before as well.  It has to do with the way that the KnowledgeAgent subscribes to resources.  I believe behind the scenes the resources are loaded in an arbitrary order.  There is a JIRA bug report already filed:

https://jira.jboss.org/jira/browse/JBRULES-2377

Hope this helps,

Steve

rules-users-bounces@lists.jboss.org wrote on 01/26/2010 01:07:29 PM:

> [image removed]

>
> [rules-users] KnowledgeAgent doesn't load dsl files and dslr file
> from a change-set correctly

>
> Pritham

>
> to:

>
> rules-users

>
> 01/26/2010 01:10 PM

>
> Sent by:

>
> rules-users-bounces@lists.jboss.org

>
> Please respond to Rules Users List

>
>
> I have a folder in classpath:
>
> dsl/global.dsl
> rules/section-A.dslr
> rules/section-A/page-1.dslr
>
> I create a knowledge base like this:
>
> public KnowledgeBase createKnowledgeBase() throws DroolsParserException,
> IOException {
>
>     KnowledgeBuilder knowledgeBuilder = KnowledgeBuilderFactory
>             .newKnowledgeBuilder();
>
>         knowledgeBuilder.add(ResourceFactory
>                 .newClassPathResource("dsl/global.dsl"),
>                 ResourceType.DSL);
>         knowledgeBuilder.add(ResourceFactory
>                 .newClassPathResource("rules/section-A.dslr"),
>                 ResourceType.DSLR);
>         knowledgeBuilder.add(ResourceFactory
>                 .newClassPathResource("rules/section-A/page-1.dslr"),
>                 ResourceType.DSLR);  
>
>     if (knowledgeBuilder.hasErrors()) {
>         throw new RuntimeException(knowledgeBuilder.getErrors().toString());
>     }
>
>     KnowledgeBase knowledgeBase = KnowledgeBaseFactory.newKnowledgeBase();
>    
> knowledgeBase.addKnowledgePackages(knowledgeBuilder.getKnowledgePackages());
>
>     return knowledgeBase;
> }
>
> // code
> knowledgeBase = createKnowledgeBase();
> session = knowledgeBase.newStatefulKnowledgeSession();
> // insert facts
> session.fireAllRules();
> session.dispose();  
>
> The above code works and I can get a unit test to work that processes rules
> accordingly. I can see my dslr converting to a drl using the "drl viewer"
> correctly (provided I temporarily place the dsl file in the same location
> since expander doesn't accept a relative path).
>
> The problem, however is when I use a change-set.xml and a KnowledgeAgent,
> things don't work
>
> code for loading via knowledgeAgent
>
> public static KnowledgeBase loadKnowledgeBase() throws
> DroolsParserException, IOException {
>     agent = KnowledgeAgentFactory.newKnowledgeAgent("msll agent");
>    
> agent.applyChangeSet(ResourceFactory.newClassPathResource("change-set.xml"));
>
>     return agent.getKnowledgeBase();
> }  
>
>
> <change-set xmlns='http://drools.org/drools-5.0/change-set'
>              xmlns:xs='http://www.w3.org/2001/XMLSchema-instance'
>              xs:schemaLocation='http://drools.org/drools-5.0/change-set.xsd'
> >
>    <add>
>        <resource source='classpath:dsl/' type='DSL' />  
>        <resource source='classpath:rules/' type='DSLR' />    
>        <resource source='classpath:rules/section-A/' type='DSLR' />
>     </add>
> </change-set>
>
>
> I get the following generic drools errors:
> ERR 103] Line 4:0 rule 'rule_key' failed predicate:
> {(validateIdentifierKey(DroolsSoftKeywords.RULE))}? in rule[7,0]: [ERR 101]
> Line 7:0 no viable alternative at input 'import' in rule Con in rule
> attribute
> ...
> ...
>
> The rules are same, folder location is the same. I believe that drools has a
> problem resolving path (expander global.dsl) from the dslr file when using a
> KnowlegeAgent since in the earlier strategy, one could build a dsl into the
> knowledgeBuilder directly from the classpath.
>
> Pl suggest.
> --
> View this message in context:
http://n3.nabble.com/KnowledgeAgent-
> doesn-t-load-dsl-files-and-dslr-file-from-a-change-set-correctly-
> tp139702p139702.html
> Sent from the Drools - User mailing list archive at Nabble.com.
> _______________________________________________
> rules-users mailing list
> rules-users@lists.jboss.org
>
https://lists.jboss.org/mailman/listinfo/rules-users