Ad-Hoc Subprocess: Support completionCondition and cancelRemainingInstances attributes

[maff]

Problem you would like to solve

camunda/camunda#28220 is adding support to configure a completionCondition and a cancelRemainingInstances attribute to ad-hoc subprocesses. This should also be configurable through the properties panel in web and desktop modeler.

An example XML definition according to the BPMN spec (see page 196):

<bpmn:adHocSubProcess id="MyAdHocSubProcess" name="My Ad-Hoc Subprocess" cancelRemainingInstances="true">
    <bpmn:extensionElements>
        <zeebe:adHoc activeElementsCollection="=[&#34;A&#34;, &#34;B&#34;]"/>
    </bpmn:extensionElements>
    <!-- incoming/outgoing, tasks, ... -->
    <bpmn:completionCondition xsi:type="bpmn:tFormalExpression">=true</bpmn:completionCondition>
</bpmn:adHocSubProcess>

Proposed solution

Make the following 2 optional attributes settings configurable through the properties panel of an ad-hoc subprocess:

Attribute	Type
completionCondition	FEEL Expression (needs to resolve to boolean)
cancelRemainingInstances	Boolean (default true)

The checklist below follows the format of the issue which initially added ad-hoc subprocess support:

• completionCondition can be defined in properties panel
  • it is FEEL
  • it is optional
• cancelRemainingInstances can be defined in properties panel
  • it is a boolean/switch
  • it defaults to true
  • ❓ TBD should this only be set when a completionCondition is defined?
• both attributes are supported in 8.8 config of camunda/bpmnlint-plugin-camunda-compat
• camunda/linting integration
  • When FEEL error is clicked, the properties panel entry is focused
  • (may be already done) Verify the errors are human-readable
• User guidance (e.g. via tooltip) and a link to documentation is provided
• Make sure documentation is released together with adding the 2 new attributes
• Integrate into camunda-bpmn-js
• Integrate into Desktop Modeler

Additional context

Needed for 8.8

[barmac]

Thanks for opening the issue. I'd like to resolve the discussion in camunda/camunda#28220 (comment) first before we move on with this.
Please note that it may be already too late to get the modeling support for 8.7 if we don't know yet whether we want it.

[barmac]

@maff @gsteyn assigning you as we agreed yesterday.