how to write condition using j-easy easy-rules to find any matching value in a set - mvel

Question

I would like to write a condition to evaluate if any one of the set values in the facts, meets the condition.
This is my rule definition:
public void evaluateRule(Facts facts, String ruleNum) {
SpRuleDefinition spRuleDefinition = spRuleDefinitionService.findByRuleNum(ruleNum);
System.out.println("Invoke Action : " + spRuleDefinition.getActionNum());
facts.put("action", "ACTION1");
MVELRule rule = new MVELRule()
.name("Rule1")
.description("My Rule")
.priority(1)
.when("shipment.orgNum=='ORG1' && (shipment.fromAddress.country=='IN' || shipment.toAddress.country=='IN') && shipment.shipmentLines.itemDetail.active==false")
.then("shipment.setOutcome(action);");
Rules rules = new Rules();
rules.register(rule);
//Fire rules on known facts
RulesEngine rulesEngine = new DefaultRulesEngine();
rulesEngine.fire(rules, facts);
}
The input that I am passing can be something like this:
{"orgNum": "ORG1", "fromAddress": { "country": "SGP"}, "shipmentLines": [{ "itemDetail": {"active": true, "countryOfOrigin": "IN"}, "itemNum": "I1", "quantity": 10 }, { "itemDetail": {"active": false, "countryOfOrigin": "US"}, "itemNum": "I2", "quantity": 1 }],"toAddress": { "country": "IN"}}
I would like to evaluate if any one of the shipment lines has itemDetail that has the active flag set to false.
The above rule fails with the following exception:
org.mvel2.PropertyAccessException: [Error: could not access: itemDetail; in class: java.util.HashSet]
[Near : {... s.country=='IN') && shipment.shipmentLines.itemDet ....}
]

Answer 1

That's a MVEL question rather than an EasyRules question.
I would like to evaluate if any one of the shipment lines has itemDetail that has the active flag set to false.
You can define a function that iterates over the set and checks your condition. Here is an example:
#Test
public void testConditionOnSet() {
Set<ItemDetail> itemDetailSet = new HashSet<>();
itemDetailSet.add(new ItemDetail(false));
itemDetailSet.add(new ItemDetail(false));
itemDetailSet.add(new ItemDetail(true));
String condition = "active = false;\n" +
"foreach (itemDetail : itemDetails) {\n" +
" active = active && itemDetail.active;\n" +
"}\n" +
"System.out.println(\"Is there a non active itemDetail?: \" + !active);";
Map facts = new HashMap();
facts.put("itemDetails", itemDetailSet);
Object result = MVEL.eval(condition, facts);
}
static class ItemDetail {
private boolean active;
public ItemDetail(boolean active) {
this.active = active;
}
public boolean isActive() {
return active;
}
}
This example prints: Is there a non active itemDetail? true.
Hope this helps.