Element order is not updated in BPMNDI

[nikku]

Describe the Bug

As mentioned in this comment the BPMN spec mandates that the order of elements in the BPMNDI section should always reflect the actual layering on the diagram.

We do ignore that fact completely and add elements to the BPMNDI section on a first created, first added basis. This results in display bugs when roundtripping with other, standards compliant tools.

Steps to Reproduce

Steps to reproduce the behavior:

• Create a task
• Create a sub process
• Move task to sub process
• Export Diagram
• Task is exported before sub process in BPMNDI

Expected Behavior

• Task position in DI is updated according to actual visibility

Note: This is not simple to accomplish, as we must effectively update all nested elements, too.

Environment

Please complete the following information:

• Browser: Any (independent)
• OS: Any (independent)
• Library version: v3.3.1

[nikku]

Idea: If we cannot get the ordering done efficiently during modeling, build a pre-export extension that normalizes things before safe. We got a few utilities that go the same route, already.

[falko]

Awesome, thx!

[barmac]

Looking forward to your feedback! It's coming with the 3.7.1 release :)