javaontologyjess

Do I have to define a rule or a query to get the name of the instance from the ontology (in a variable)?

My instances have names (screenshot of the said names in Protégé) and slots (image here).

What I need to do is: knowing the value of the slot "DESCRIPTION", getting the name of the instance so I can use it in my Java program.

I thought of a defrule, but does it allow me to have the result in a global variable? Can you please guide me in doing this?

Solution

  • You can indeed use a rule in combination with a global:

    (defglobal ?*desc* = "")

    Write a rule:

    (defrule getDescription
    (SystemEauDeRefroidissement
       (http..#description ?d))
=>
    (bind ?*desc* ?d))

    This might work if you have only a single instance of SystemEauDeRefroidissement. You can retrieve the global's value using the Jess API:

    Context ctxt = rete.getContext();
Variable var = ctxt.getVariable( "desc" );
String desc = var.stringValue( ctxt );

    I haven't tested any of this.

    Edit If you have the description, you may write a rule (now more in the Protégé style:

    (object
   (is-a http..#SystemEauDeRefroidissement) 
   (OBJECT ?sedr)
   (http..#description ...)
=>
    (bind ?*sedr* ?sedr))

    I don't know how you'd like to insert the description value into the Jess environment, so that's why there's the ellipsis.