I'm using `activiti-spring-boot-starter:7.1.0.M6`.
As I read [document][1], to pass process varibles to sub-process, I need to use
<!-- Main Process -->
<bpmn:callActivity id="mainActivity" name="TASK_NAME" calledElement="subProcess">
<bpmn:extensionElements>
<activiti:in target="subVarName" source="mainVarName"/>
<activiti
ut target="mainVarName2" source="subVarName2"/>
</bpmn:extensionElements>
<bpmn:incoming>flow1</bpmn:incoming>
<bpmn
utgoing>flow2</bpmn
utgoing>
</bpmn:callActivity>
After I passed the variable, I thought it would be OK that process call `subVarName` in bpmn, but it wasn't.
I got `UnknownPropertyException` when engine referred `subVareName`.
<!-- Sub Process -->
<bpmn:serviceTask id="subActivity" name="SUB_TASK_NAME"
activiti:expression="${mySpringService.method(subVarName, execution)}">
<bpmn:incoming>subFlow1</bpmn:incoming>
<bpmn
utgoing>subFlow2</bpmn
utgoing>
</bpmn:serviceTask>
I already checked that `mainVarName` is not null because it is used by prior service task in main process.
Please let me know what I missed... Thanks!
[1]: https://www.activiti.org/userguide/#bpmnCallActivityPassVariables