Increase extracting capabilities

[pinussilvestrus]

What should we do?

Currently, we only extract variables from camunda:outputParameter properties. We should investigate whether we can increase these, e.g. by resultVariables from script tasks.

• [x] Create a list of (reliable) process variable sources
• [x] Update extracting mechanism by those properties
  • [x] result variables (cf. moddle descriptors)
  • [x] form field ids (cf. moddle descriptors)
  • [x] call activity out mappings

Why should we do it?

More process variables suggestions to work with.

[volkergersabeck]

Additional sources are:

• Result Variable of Script Task or ServiceTaskLike elements (cf. https://github.com/camunda/camunda-bpmn-moddle/blob/master/resources/camunda.json#L422)
• Form Field IDs (user tasks or start events) (cf. https://github.com/camunda/camunda-bpmn-moddle/blob/master/resources/camunda.json#L972)
• (maybe?) Out mapping of Call Activities
• OutputMappings of Intermediate Events

[pinussilvestrus]

OutputMappings of Intermediate Events

this should already be included