How to update a variable in an activity diagram during simulation?

Question

I am working on an activity diagram that contains several actions, each with a tagged value called i: int . This activity diagram has a context block named "context" with a value variable sum: int = 0 .

I want to update the "sum" during the simulation, such that

sum = sum + i

For example, after simulating this diagram, sum should become 5 (i_action1 = 2 and i_action2 = 3)

Could someone provide guidance on how to model this? Specifically, how can I retrive the value of i in a clear and effective way? I tried with opaque action, with groovy code

sum = sum + ALH.getTagValue(this, “i”);

But it doesn't work, because "this" is the script, not my action. I tried also with this.getOwner() and this.getCaller() and self, but no luck.

Any examples or best practices would be greatly appreciated!

Thank you!

Answer 1

The following python script works with my version of the simulation engine:

def getTagValueOfCurrentAction(tagName):
   namedElement = ALH.getCaller()
   taggedValues = namedElement.getTaggedValue()
   for v in taggedValues:
    if v.getTagDefinition().getName() == tagName:
         return v.getValue()[0]


print (getTagValueOfCurrentAction("i"))

I think the reason why the helper doesn't work, is that no runtime object is created for an opaque action.

PS: You probably have a good reason for using a stereotype attribute (on language level) to calculate a block attribute (on user model level). If not, you could replace them with value pins. I think it would be much easier to use them in the script.