Unable to change lifecycle

[ocroquette]

Hi

I have an already elaborate sequence diagram.
When I try to add a "new" message between 2 existing lifelines (ie. so that the source object "creates" the destination object), I typically get the following error message:

Message Validation Error : Unable to change lifecycle

It's not very useful.
Does someone know what the problem is?
Is there another solution than to start the diagram from scratch!?

Thanks

[Frank Horn]

Just drag the new message to the top (so it's the first message going to the lifeline to be created), and then you can select the "New" option in the "Lifecycle" combo.

If you want a message which is not the first one to create a lifeline, this means that you think of your target lifeline not representing an instance of a class but multiple instances, which is not in accordance with the OMG UML Specification. You would have to add a second lifeline for the second instance.

Unfortunately, EA will give you a stupid message if you drag a class from the Project Browser to your diagram a second time ("This diagram already contains an instance blah blah blah"). You will have to use the "Advanced - Convert to Instance" context menu on your first target lifeline first.

[ocroquette]

OK, I will describe the problem better:

I create a new message at the top:



If I choose "New" in the opening dialog related to the new message, I get the error message.

If I close the dialog, I can see that a new message has been created anyway (however, not a "new", rather a normal one):



If I open again the properties of this message, and then set it to "New", then it works:



That it doesn't work in the first place seems to me as a bug.

[Frank Horn]

You're right. It looks like only the first message to a lifeline can be created with the "New" option, while for all messages created later you have to close the dialog first, reopen it and then choose "New".

If this not a bug, then it's at least a nuisance. They probably never tested it that way, but always drew the initializing message first. Maybe we're supposed to know from the start when our objects will be created. But then if we new everything from the start, we wouldn't really need a modelling tool at all...

[«Midnight»]

I've got to agree with Frank here.

As long as we're using EA for modeling, this needs to be reported as a bug.

David