DMN input, accessing json variable and querying the path

Vamshidhar_Reddy_Chi · August 22, 2021, 6:51pm

Hi
I have a DMN table with input column and the input should check for a property in a string(Which is in JSON format).
From unit test I am setting the input variables with JSON as value.

String data = “{\n”
+ " "Data":{\n"
+ " "appealType":"test"\n"
+ " },\n"
VariableMap inputVariables = new VariableMapImpl();
inputVariables.putValue(“CaseField”, data);

What would be the FEEL expression to access the property appealType, to be used in DMN input column.

Thanks
Vam

hassang · August 23, 2021, 2:31am

Hi @Vamshidhar_Reddy_Chi,

Assuming CaseField is a variable of json type

Below snip shows how to use json variable

// define a JSON variable
SpinJsonNode json = Spin.JSON("{\"customer\": \"Kermit\", \"language\": \"en\"}");
  
// create a variable map and store the JSON variable
VariableMap variables = Variables.createVariables().putValue("jsonVariable", json);

Vamshidhar_Reddy_Chi · August 23, 2021, 12:37pm

What is the json expression I can use in DMN input column? Screenshot 2021-08-23 at 13.37.04

hassang · August 23, 2021, 1:23pm

Hi @Vamshidhar_Reddy_Chi ,
If you change expression language to JUEL then you can use below expression
JSON(CaseField).prop("appealType").stringValue()

Vamshidhar_Reddy_Chi · August 23, 2021, 2:09pm

This is my json
String caseField = “{\n”
+ " “Data”:{\n"
+ " “appealType”:“refusalOfHumanRights”,\n"
+ " }"
+ “}”;

final SpinJsonNode json = Spin.JSON(caseField);
inputVariables.putValue(“CaseField”, json);

My DMN looks like ,

I get following error when test is executed,

DMN-01002 Unable to evaluate expression for language ‘juel’: ‘${JSON(CaseField).prop(“Data”).prop(“appealType”).stringValue()}’
org.camunda.bpm.dmn.engine.impl.DmnEvaluationException: DMN-01002 Unable to evaluate expression for language ‘juel’: ‘${JSON(CaseField).prop(“Data”).prop(“appealType”).stringValue()}’
at org.camunda.bpm.dmn.engine.impl.DmnEngineLogger.unableToEvaluateExpression(DmnEngineLogger.java:38)
at org.camunda.bpm.dmn.engine.impl.evaluation.ExpressionEvaluationHandler.evaluateElExpression(ExpressionEvaluationHandler.java:125)
at org.camunda.bpm.dmn.engine.impl.evaluation.ExpressionEvaluationHandler.evaluateExpression(ExpressionEvaluationHandler.java:62)
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)
at org.camunda.bpm.dmn.engine.impl.DefaultDmnEngine.evaluateDecisionTable(DefaultDmnEngine.java:115)
at org.camunda.bpm.dmn.engine.impl.DefaultDmnEngine.evaluateDecisionTable(DefaultDmnEngine.java:105)
at uk.gov.hmcts.reform.iataskconfiguration.DmnDecisionTableBaseUnitTest.evaluateDmnTable(DmnDecisionTableBaseUnitTest.java:32)
at uk.gov.hmcts.reform.iataskconfiguration.dmn.CamundaTaskInitiationTest.given_multiple_event_ids_should_evaluate_dmn(CamundaTaskInitiationTest.java:94)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:688)
at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestTemplateMethod(TimeoutExtension.java:92)
at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:210)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:206)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:131)
at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:65)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$DefaultDynamicTestExecutor.execute(NodeTestTask.java:212)
at org.junit.platform.engine.support.hierarchical.NodeTestTask$DefaultDynamicTestExecutor.execute(NodeTestTask.java:192)
at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:139)
at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.lambda$execute$2(TestTemplateTestDescriptor.java:107)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
at java.base/java.util.stream.ReferencePipeline$11$1.accept(ReferencePipeline.java:442)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.Streams$StreamBuilderImpl.forEachRemaining(Streams.java:411)
at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:658)
at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:274)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:274)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1655)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:274)
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1655)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:107)
at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:42)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:248)
at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$5(DefaultLauncher.java:211)
at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:226)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:199)
at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:132)
at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.processAllTestClasses(JUnitPlatformTestClassProcessor.java:99)
at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor$CollectAllTestClassesExecutor.access$000(JUnitPlatformTestClassProcessor.java:79)
at org.gradle.api.internal.tasks.testing.junitplatform.JUnitPlatformTestClassProcessor.stop(JUnitPlatformTestClassProcessor.java:75)
at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:61)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:33)
at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter.java:94)
at com.sun.proxy.$Proxy5.stop(Unknown Source)
at org.gradle.api.internal.tasks.testing.worker.TestWorker.stop(TestWorker.java:133)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:36)
at org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24)
at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:182)
at org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:164)
at org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:414)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:64)
at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:48)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:56)
at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: javax.el.ELException: Could not resolve function ‘JSON’
at de.odysseus.el.tree.Tree.bind(Tree.java:125)
at de.odysseus.el.TreeValueExpression.(TreeValueExpression.java:73)
at de.odysseus.el.ExpressionFactoryImpl.createValueExpression(ExpressionFactoryImpl.java:445)
at org.camunda.bpm.dmn.engine.impl.el.JuelElProvider.createExpression(JuelElProvider.java:62)
at org.camunda.bpm.dmn.engine.impl.evaluation.ExpressionEvaluationHandler.evaluateElExpression(ExpressionEvaluationHandler.java:115)
… 155 more

I have added dependency ‘org.camunda.spin’, name: ‘camunda-spin-dataformat-json-jackson’, version: ‘1.11.0’

hassang · August 23, 2021, 2:16pm

I see that you are using a json variable so using FEEL input expression CaseField.Data.appealType should do the job

Vamshidhar_Reddy_Chi · August 23, 2021, 2:25pm

I tried with above Feel expression, I get this error

FEEL/SCALA-01008 Error while evaluating expression: failed to evaluate expression ‘CaseField.Data.appealType’: context contains no entry with key ‘Data’
org.camunda.bpm.dmn.feel.impl.FeelException: FEEL/SCALA-01008 Error while evaluating expression: failed to evaluate expression ‘CaseField.Data.appealType’: context contains no entry with key ‘Data’

hassang · August 23, 2021, 3:20pm

Hi @Vamshidhar_Reddy_Chi,

I believe your json string is badly structured
Please try below assignement

String caseField = "{\"Data\": {\"appealType\": \"refusalOfHumanRights\"}}";

Vamshidhar_Reddy_Chi · August 23, 2021, 3:26pm

I don’t think so, if the json is invalid before evaluating the dmn expression Spin throws json format error.

I tried with exact same string which you have given, still I get same error.

hassang · August 23, 2021, 3:38pm

Hi @Vamshidhar_Reddy_Chi,

Can you please share your code…(the full Java class)

Vamshidhar_Reddy_Chi · August 23, 2021, 4:15pm

test-dmn.dmn (1.9 KB)
Processing: DmnJsonValueTest.java…
DmnCode.txt (2.8 KB)

hassang · August 23, 2021, 7:33pm

Hi @Vamshidhar_Reddy_Chi ,

Both below dependencies should be added

<dependency>
	<groupId>org.camunda.bpm</groupId>
	<artifactId>camunda-engine-plugin-spin</artifactId>
	<version>${version.camunda}</version>
</dependency>

<dependency>
	<groupId>org.camunda.spin</groupId>
	<artifactId>camunda-spin-dataformat-json-jackson</artifactId>
	<version>1.11.0</version>
</dependency>

In the case of a standalone DMN Engine setup, the Spin Process Engine Plugin would need to be added as a dependency as well

Vamshidhar_Reddy_Chi · August 24, 2021, 1:21pm

After adding dependency, camunda-engine-plugin-spin, the test passed.

Is there any alternative way to read json string using FEEL/JUEL EL without using SPIN integration.

hassang · August 24, 2021, 1:59pm

Hi @Vamshidhar_Reddy_Chi,

I don’t think so. SPIN is required.

system · January 30, 2024, 1:18pm