Get swimlane from an activity

[nekron...@gmail.com]

Hi @ll,

I want to get the swimlane an activity belongs to using the Camunda API. How can I do so?
Thanks for your help in advance!

Greetz
Alex

[Daniel Meyer]

Hi Alex,

what do you mean by "Swimmlane"? Do you mean the lane in BPMN?

<process id="invoice" name="invoice receipt" isExecutable="true">
    <laneSet id="laneSet_5">
      <lane id="Approver" name="Approver">
        <flowNodeRef>approveInvoice</flowNodeRef>
        <flowNodeRef>invoice_approved</flowNodeRef>
      </lane>
      <lane id="teamAssistant" name="Team Assistant">
        <flowNodeRef>reviewInvoice</flowNodeRef>
        <flowNodeRef>reviewSuccessful_gw</flowNodeRef>
        <flowNodeRef>assignApprover</flowNodeRef>
        <flowNodeRef>StartEvent_1</flowNodeRef>
        <flowNodeRef>invoiceNotProcessed</flowNodeRef>
      </lane>
      <lane id="Accountant" name="Accountant">
        <flowNodeRef>prepareBankTransfer</flowNodeRef>
        <flowNodeRef>invoiceProcessed</flowNodeRef>
        <flowNodeRef>ServiceTask_1</flowNodeRef>
      </lane>
    </laneSet>

If you want to find the lane for the activity "prepareBankTransfer" you can use the bpmn model API.

First you have to get the model instance of your process. The way to get the model depends on whether you are calling the service API of the engine or whether you are implementing a Service Task or Task Listener. 

    // EITHER (1) service API
    BpmnModelInstance model = repositoryService.getBpmnModelInstance("...");  

If you are impementing a service task or listener, you can always get the current model instance:

    // OR (2) inside a JavaDelegate / TaskListener ... (while executing the process)
    BpmnModelInstance model = delegateExecuton.getBpmnModelInstance();

Once you have retrieved the model instance you can simply iterate:

    // find all lanesets within the model
    Collection<LaneSet> laneSets = model.getModelElementsByType(LaneSet.class);
    for (LaneSet laneSet : laneSets) {
     
      //iterate the lanes
      Collection<Lane> lanes = laneSet.getLanes();
      for (Lane lane : lanes) {
       
        // check the flow nodes
        Collection<FlowNode> flowNodeRefs = lane.getFlowNodeRefs();
        for (FlowNode flowNode : flowNodeRefs) {
         
          // check the id. (note that you can do the check based on aly attribute (also from custom namespace) or child element
          if ("prepareBankTransfer".equals(flowNode.getId())) {
            // found the lane!
          }
        }
      }


    }

Note that accessing the BpmnModelInstance is fast since the model instance is cached.

Does this help?

Daniel

[nekron...@gmail.com]

Hi Daniel!

Thanks for your answer and that's exactly what I need.
But I have a problem with your code.

The LaneSet.class can't be used for the getModelElementsByType method. I get the following exception:

The method getModelElementsByType(ModelElementType) in the type ModelInstance is not applicable for the arguments (Class<LaneSet>)

I am using Camunda 7.1-Final.

Thanks in advance!

[nekron...@gmail.com]

Hi Daniel,

Forget about my last message, I was still using 7.1-alpha 4 ;).
Everything is working fine!
Thanks a lot for your help!


Greetz
Alex