How to create a input condition based on List as input

BPMN & Modeling Discussion & Questions
1

Greeting fellow user. I am looking for a solution to a very specific input condition.

Lets say i want to define an input condition based on a list of cars.
Input - If car doesn’t belong to [“HONDA”,“KIA”,“FORD”]
Output - We don’t support the car.

In modeler, we have currently defined this condition as not["HONDA","KIA","FORD"]
We tried defining as not(["HONDA","KIA","FORD"]) as well. But it didn’t work in FEEL
However somehow even if I pass Honda in input object, it still fails to recognize the input is correct.
Am i missing something. Appreciate your inputs.
Many Thanks.

2

Hi @Nishikant_Karanjkar,

try the following FEEL expression:

not("HONDA", "KIA", "FORD")

Note that the matching is case-sensitive.

Does this help you?

Best regards,
Philipp

3

Hello,

Apologies for long post.
My Java Test class looks like

public class TestCarDecisionService {
    @Rule
    public DmnEngineRule dmnEngineRule = new DmnEngineRule();
    private DmnEngine dmnEngine;

    @Before
    public void setup(){
        dmnEngine  = dmnEngineRule.getDmnEngine();
    }

    @Test
    public void test(){
      Car car = new Car("FONDA", Arrays.asList("FONDA"));
      try(InputStream inputStream = new FileInputStream("c:\\temp\\carChecker.dmn")){
          ObjectValue value = Variables.objectValue(car).create();
          VariableMap map = createVariables().putValue("Car", value);
          DmnDecisionTableResult result = dmnEngine.evaluateDecisionTable("carChecker", inputStream, map);
          System.out.println(result.toString());
          System.out.println(result.getResultList().toString());
          System.out.println(result.getSingleResult().toString());
      } catch (IOException e) {
            e.printStackTrace();
      }
  }

  private class Car{
    private String name;
    private List<String> carType;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Car(String name, List<String> classification) {
        this.name = name;
        this.carType = classification;
    }
  }
}

And my DMN table is

<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/DMN/20151101/dmn.xsd" xmlns:camunda="http://camunda.org/schema/1.0/dmn" id="Definitions_03ii53t" name="DRD" namespace="http://camunda.org/schema/1.0/dmn" exporter="Camunda Modeler" exporterVersion="3.7.1">
  <decision id="carChecker" name="carChecker">
    <decisionTable id="decisionTable_1" hitPolicy="FIRST">
      <input id="input_1" label="carType" camunda:inputVariable="car.carType">
        <inputExpression id="inputExpression_1" typeRef="string" expressionLanguage="FEEL">
          <text>list contains(car.carType, "HONDA"),
list contains(car.carType, "FORD"),list contains(car.carType, "KIA"),</text>
        </inputExpression>
      </input>
      <output id="output_1" label="carChoice" name="carChoice" typeRef="string" />
      <rule id="DecisionRule_1a0ynk0">
        <inputEntry id="UnaryTests_1fhlsse">
          <text>not("Ford","Kia","Honda")</text>
        </inputEntry>
        <outputEntry id="LiteralExpression_0av5iv1">
          <text>"not a ford kia or honda"</text>
        </outputEntry>
      </rule>
      <rule id="DecisionRule_1j23l7h">
        <inputEntry id="UnaryTests_1dbovkg">
          <text></text>
        </inputEntry>
        <outputEntry id="LiteralExpression_19k3ii1">
          <text>"A ford, kia or honda"</text>
        </outputEntry>
      </rule>
    </decisionTable>
  </decision>
</definitions>

I want to implment

  1. The input will be list of car names passed (Car car = new Car(“FONDA”, Arrays.asList(“FONDA”)))
  2. The condition is if the car object list doesnt belong to list of defined rule i.e. not(“HONDA”,“FORD”,“KIA”)
  3. Output should be shown as the reject reason ->“not a ford, kia or honda”

I tried few suggestion to use FEEL language however no luck.
I keep getting below exception

FEEL-01016 Simple Expression not supported by FEEL engine
java.lang.UnsupportedOperationException: FEEL-01016 Simple Expression not supported by FEEL engine
	at org.camunda.bpm.dmn.feel.impl.juel.FeelEngineLogger.simpleExpressionNotSupported(FeelEngineLogger.java:160)
	at org.camunda.bpm.dmn.feel.impl.juel.FeelEngineImpl.evaluateSimpleExpression(FeelEngineImpl.java:48)
	at org.camunda.bpm.dmn.engine.impl.evaluation.ExpressionEvaluationHandler.evaluateFeelSimpleExpression(ExpressionEvaluationHandler.java:130)
	at org.camunda.bpm.dmn.engine.impl.evaluation.ExpressionEvaluationHandler.evaluateExpression(ExpressionEvaluationHandler.java:59)
	at org.camunda.bpm.dmn.engine.impl.evaluation.DecisionTableEvaluationHandler.evaluateInputExpression(DecisionTableEvaluationHandler.java:193)
	at org.camunda.bpm.dmn.engine.impl.evaluation.DecisionTableEvaluationHandler.evaluateInput(DecisionTableEvaluationHandler.java:122)
	at org.camunda.bpm.dmn.engine.impl.evaluation.DecisionTableEvaluationHandler.evaluateDecisionTable(DecisionTableEvaluationHandler.java:104)
	at org.camunda.bpm.dmn.engine.impl.evaluation.DecisionTableEvaluationHandler.evaluate(DecisionTableEvaluationHandler.java:81)
	at org.camunda.bpm.dmn.engine.impl.DefaultDmnDecisionContext.evaluateDecision(DefaultDmnDecisionContext.java:85)[carChecker.dmn|attachment](upload://9Iidps1C5hYPS00Ut82sNnVnbPO.dmn) (1.4 KB) [TestCarDecisionService.java.txt|attachment](upload://mm51j9MPahsLUkf63ZLzK6jH99C.txt) (1.9 KB)
4

Hi,

Have a look at this blog post. Perhaps the sample DMN in this blog post may inspire a solution approach…

regards

Rob

5

Hello Rob,

Thanks for response. I don’t see the List input validation against list. Could you pls share the DMN tables so can take a closer look ? Many thanks.

6

Hi @Nishikant_Karanjkar,

Try to use Camunda BPM 7.13.

7

Hi,

Here’s an example where I used list contains…

regards

Rob

Accreditation_Management_FEEL.dmn (12.4 KB)

8