Drools step by step FireKB example / published by https://github.com/dacr/code-examples-manager #44b1c8d3-d07d-4650-8476-a599b49c4ee7/d26cecee2ffdaaf7d55144b1f9ae0f7867828329

drools-kb-official-examples-simple-with-pauses.sc

// summary : Drools step by step FireKB example
// keywords : scala, drools, mvel, ai, knowledgebase
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : 44b1c8d3-d07d-4650-8476-a599b49c4ee7
// created-on : 2019-10-23T23:00:03+02:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.5.1"
//> using dep "org.drools:drools-examples:9.44.0.Final"
// ---------------------

def pause(msg:String):Unit = {
  println("- - - - - - - - - - - - - - - - - - - - - - -")
  System.out.println(msg)
  println("=============================================")
  System.in.read()
}

pause("USE ENTER KEY TO CONTINUE ON NEXT STEP")

pause( // TODO update for scala-cli -repl
  """import $ivy.`org.drools:drools-examples:7.44.0.Final`
    |  Dynamic loading of this library, it'll also load all related sub dependencies
    |  This jar contains all drools example knownledge bases. Both DRL files and all
    |  the compiled java classes they may use. The configuration file for all defined
    |  knowledge bases is store within the META-INF/kmodule.xml within this jar.
    |""".stripMargin
)


import org.kie.api._, org.kie.api.runtime._
pause(
  """import org.kie.api._, org.kie.api.runtime._
    |  Brings required classes in the current scope. Allow us for example to have direct
    |  access for example to the KieServices class without to specify its full path which
    |  is "org.kie.api.KieServices"
    |""".stripMargin
)


val kServices = KieServices.Factory.get
pause(
  """val kServices = KieServices.Factory.get
    |  The main entry point to all DROOLS API. Returns the access singleton.
    |""".stripMargin
)

val kContainer = kServices.getKieClasspathContainer()
pause(
  """val kContainer = kServices.getKieClasspathContainer()
    |  Get the a classpath KIE container which allow us to list all available
    |  knowledge bases, and also to create one from its declared name. In fact
    |  it will search for all available META-INF/kmodule.xml in the class path,
    |  some coming from the current application or other coming from loaded
    |  dependencies.
    |""".stripMargin
)

val kbNames = kContainer.getKieBaseNames
println(kbNames)
pause(
  """val kbNames = kContainer.getKieBaseNames
    |println(kbNames)
    |  Get the names of all available knowledge bases. The names as those declared
    |  in found META-INF/kmodule.xml such as "FireKB" for :
    |    <?xml version="1.0" encoding="UTF-8"?>
    |    <kmodule xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    |           xmlns="http://www.drools.org/xsd/kmodule">
    |    ...
    |    <kbase name="FireKB" packages="org.drools.examples.fire.simple">
    |    ...
    |""".stripMargin
)

val kbase = kContainer.getKieBase("FireKB")
pause(
  """val kbase = kContainer.getKieBase("FireKB")
    |  Create the knowledge base API entry point, from which we can
    |  get information about available rules, declarations, ... Through
    |  this API we can also create an execution session to start the
    |  expert system.
    |""".stripMargin
)

val session = kbase.newKieSession()
pause(
  """val session = kbase.newKieSession()
    |  Create a DROOLS statefull session, start the expert system and
    |  provide all method to interact with the expert system.
    |  insert, fireAllRules, fireUntilHalt, delete, ... methods.
    |""".stripMargin
)

import org.drools.examples.fire._
pause(
  """import org.drools.examples.fire._
    |  The FireKB knowledge base uses fact type declared from java code
    |  (not declarations within drl files) so in order to create we need
    |  to import the classes from the place they reside.
    |""".stripMargin
)

val fireFact = new Fire(new Room("42"))
pause(
  """val fireFact = new Fire(new Room("42"))
    |  Create a Fire fact which has been detected in Room 42.
    |  The create fire instance is going to be added to drools working memory
    |""".stripMargin
)

session.insert(fireFact)
pause(
  """session.insert(fireFact)
    |  The fact fireFact is inserted into drools working memory.
    |""".stripMargin
)

session.fireAllRules()
pause(
  """session.fireAllRules()
    |  Ask drools to fire all rules which can be fired up. This method will
    |  return only when no more rules can be run.
    |""".stripMargin
)