[protege-discussion] PAL ValidationErrorImpl errors when using API but not GUI

[Samson Tu]

Open your pal.jar file with Winzip and verify that the manifest.mf file 
has entries like:

Name: edu/stanford/smi/protegex/pal/predicates/LessThanP.class
PAL-Predicate: True

Make sure that your are using the same jar files and jvm 
programmatically as Protege GUI.

I am not aware of any change made to PAL in recent years.

Samson


Bertram Stuart wrote:
> Hi,
> 
> I have an application that uses a Protege ontology (pprj format) and a 
> number of PAL rules for validation. Those PAL rules are called through 
> the API, looping over each constraint and calling the following:
> 
> 
> EvaluationPolicy evalPolicy = new EvaluationPolicy();
> evalPolicy.setFindAllCounterExamples(true);
> ConstraintEvaluationEngine evalEngine = new 
> ConstraintEvaluationEngine(evalPolicy, kb);
> ConstraintEngineResponse response = 
> evalEngine.checkSingleStatement(palConstraint);
> Collection<ConstraintViolation> constraintResult = null;
> 
> if (response.areThereValidationErrors())
> {
> 	for (Object obj : response.getValidationErrors(palConstraint))
> 	{
> 		log.warn(obj.toString());
> 	}
> }
> else if (response.areThereConstraintViolations())
> {
> 	constraintResult = response.getConstraintViolations(palConstraint);
> 	log.info("Number of violations of " + palConstraint.getBrowserText() + 
> " = " + constraintResult.size());
> }
> else
> {
> 	log.info("No constraint violations for " + palConstraint.getBrowserText());
> }
> 
> 
> palConstraint is an Instance that is the constraint and kb is the 
> KnowledgeBase that the palConstraint was taken from and should be 
> checked against. log is just a Log4J logger.
> 
> This has worked perfectly fine until recently, when it has started 
> failing to parse the PAL rules and instead returning ValidationErrorImpl 
> errors. The rules themselves are perfectly fine, as I can run them from 
> within Protege and they pass/fail as appropriate. The problem is only 
> from API calls, which get messages like the following:
> 
> 	Predicate named < is referenced but not defined.
> 	Predicate named > is referenced but not defined.
> 	Function named number-of-own-slot-values is referenced but not defined.
> 	Function named coerce-to-string is referenced but not defined.
> 
> Given that the predicates and functions are core functionality, I am at 
> a loss as to how they can not be defined. I have the protege.jar (3.3.1 
> and 3.2.1 have been tested), lax.jar and looks-2.1.3.jar files from the 
> Protege folder, plus antlr.jar and pal.jar from the plugins all included 
> in my project.
> 
> Any suggestions on what might be causing core predicates and functions 
> to fail as "not defined", especially when it works from the Protege app 
> and worked as API calls until recently?