Getting InputParameter variables of Task using Java API

Camunda 7 Topics Discussion & Questions
1

How do we get inputParameter variable values using java code ?

  <cmmn:humanTask id="HumanTask_0xmmxjm" camunda:assignee="john" camunda:formKey="PatientDetails!f4370f84-4c53-423f-b28a-72573c2bfa14">
     <cmmn:extensionElements>
         <camunda:inputOutput>
           <camunda:inputParameter name="formArg">${formArg}</camunda:inputParameter>
           <camunda:outputParameter name="outcome" />
         </camunda:inputOutput>
     </cmmn:extensionElements>
  </cmmn:humanTask>
2

Hi @Suhas_Kulkarni, if you are trying to get the inputParameter from a JavaDelegate, you just need to call the method getVariable:

execution.getVariable(“formArg”);

but if not, you can get from the runtimeService

@Autowired private RuntimeService runtimeService;
@Autowired private TaskService taskService;

// get the task using the task Id
Task task = taskService.createTaskQuery().taskId(“your_task_id”).singleResult();

// get the execution using the execution Id
Execution execution = runtimeService.createExecutionQuery().executionId(task.getExecutionId()).singleResult();
execution.getVariable(“formArg”);

3

Thanks Kyle. Also Is there a camunda built in API that returns that?

4

I have case human task and used TaskCreationListener for reading variable -
execution.getVariable(“formArg”);

But I always get null value for above call. Any idea? JavaDelegate can only be attached to Service task and not human task right?

5

@Suhas_Kulkarni can you upload your model and in which activity you’re trying to access the form variables?

6

Below is my CMMN model with humanTask having inputParameter. I have process variable called “formArg” and it has value. but execution.getVariable(“payload”) is returning null. What can be issue?

<cmmn:humanTask id=“HumanTask_0xmmxjm” camunda:assignee=“ssaInstanceAdmin” camunda:formKey=“PatientDetails!f4370f84-4c53-423f-b28a-72573c2bfa14”>
cmmn:extensionElements
camunda:inputOutput
<camunda:inputParameter name=“payload”>${formArg}</camunda:inputParameter>
<camunda:outputParameter name=“outcome” />
</camunda:inputOutput>
<camunda:taskListener class=“com.oracle.process.approval.listener.dp.TaskCreationListener” event=“create” />
</cmmn:extensionElements>
</cmmn:humanTask>

7

variable is referenced in TaskCreationListener

8

Have you tried using Formservice in task Listener?

String taskId = delegateTask.getId();
FormService formService = delegateTask.getProcessEngineServices().getFormService();
TaskFormData taskFormData = formService.getTaskFormData(taskId);
9

Hi Arvind
TaskCreationListener attached to humanTask has access to DelegateCaseExecution
and I use delegateCaseExecution.getVariableLocal(“payload”). This returns null.
I was thinking “payload” inputParameter variable should have value assigned from ${formArg}.

I tried using formService that you mentioned but we use external forms and that really doesn’t fit and doesn’t work for me.

10

What I meant is I don’t get value of “x” variable in TaskCreationListener using execution.getVariable(“x”) for this input -
<camunda:inputParameter name=“x”>foo</camunda:inputParameter>

12

Refer this post,

13

Thanks Arvind

I still did not get value of InputParameter in TaskListener class . Here is my cmmn snippet -
<cmmn:humanTask name=“Provide Customer Rating” id=“HumanTask_2” camunda:assignee=“demo”>
cmmn:extensionElements
camunda:inputOutput
<camunda:inputParameter name=“x”>6</camunda:inputParameter>
<camunda:outputParameter name=“outcome” />
</camunda:inputOutput>
</cmmn:humanTask>

Here is my TaskListener implements TaskListener {
public void notify(DelegateTask delegateTask) {
DelegateCaseExecution execution = delegateTask.getCaseExecution();
String payload = (String) execution.getVariable(“x”); // returns null
payload = (String) execution.getVariableLocal(“x”); // returns null too.
}
}

14

Hi @kyle
I’m still not able to get inputParameter value in TaskListener (task create event). I can not use JavaDelegate as this is humanTask and not serviceTask. What am I doing wrong ?

Here is my cmmn snippet -
<cmmn:humanTask name=“Rating” id=“HT_2” camunda:assignee=“demo”>
.cmmn:extensionElements
.camunda:inputOutput
<camunda:inputParameter name=“x”>6</camunda:inputParameter>
</camunda:inputOutput>
</cmmn:extensionElements>
</cmmn:humanTask>

Here is my TaskListener implements TaskListener {
public void notify(DelegateTask delegateTask) {
DelegateCaseExecution execution = delegateTask.getCaseExecution();
String x = (String) execution.getVariable(“x”); // returns null
x = (String) execution.getVariableLocal(“x”); // returns null too.
x = runtimeService.getVariablesLocal(task.getExecutionId()); // throws error //execution does not exist
}
}

15

hi @Suhas_Kulkarni, I’m still newbie with CMMN, but is it possible to define inputParameter inside Human Task? Apparently camunda modeler doesn’t has this option

16

Thanks. Not sure if there is support for input/output for CMMN humanTask ?

17