Sequence objects not underlined in v12

[damo1978]

Could anybody explain why my objects in the sequence diagrams since version 12 are no longer underlined to represent an object instance vs. a class?

I've search as many visual options as I could find.

[qwerty]

Maybe because UML 2.5 does not (no longer) use underlines? P. 622 of SS 2.5 ptc/2013-09-05 shows them without underline (though instances still appear underlined).

Also looked into 2.1.1 and it's without underline there too. Maybe it's some heritage from very old UML versions. 1.5 and 2.0 use this notation.

q.

[damo1978]

Thanks.  I've just searched through 2.4.1 which states that an underline is required to differentiate between an object instance and a class, as has always been the way.  Didn't realise EA12 was 2.5.

In the 2.5 spec it also refers to instances being concatenate-underlined (9.8.4 p.129), as it was in 2.4.1.  I've also checked the sequence diagram section you referred to which is the same as 2.4.1.  There doesn't seem to be anything explicit.

All I know is that now I'm having to do this as part of my Open Uni course, they are marking me down because I'm not underlining them.  In the last 10 years of using Sparx and UML, it has always underlined lifeline instances.

[damo1978]

I've added some images to help understand the issue in case it's not clear.

The first image shows what EA is doing (in purple), and the second is what I'm wanting it to do, which I'm now having to manually do using the font style.

screen shot windows

Second image

image hosting free

[qwerty]

Funny enough I had opened 9.3 because of your other issue. And there it appears without underline too. I seem to remember having it seen underlined in the past but 9.3 is the eldest version of EA I keep. Maybe a Sparxian can shed light on this.

q.

[damo1978]

Thanks for checking.  I've emailed Sparx support to see if they can shed some light.

[Eve]

Just did a quick check of the UML specification. While I didn't find a definitive reference that says that lifelines shouldn't be underlined. All example lifelines I found were instances (eg. :A as the name) and none were underlined.

Edit: Actually, I take it back. The underline represents an instance of InstanceSpecification. A Lifeline directly inherits from NamedElement, and explicitly defines the ':' notation for the connectable element that the lifeline represents.

[damo1978]

Thanks Simon.

There is a section (9.8.4 p.129) highlighting that there should be when distinguishing between objects and classes, i.e. they should contain a concatenated-underline.

It's also common practice and is well documented across the Google-sphere.  It used to be in EA but it's seems to have stopped somewhere.

[Eve]

Just to be clear (and ensure you see my edit)

9.8.4 Defines the notation for an InstanceSpecification which includes underline and : <classifier>.

Figure 17.6 Shows that lifelines inherit directly from NamedElement (not InstanceSpecification)
17.3.4 Defines the notation for lifelines. It includes : <connectable-element-type> but no mention of underlining.

If underline is common practice, then people with more influence than knowledge have misinterpreted the specification.

[damo1978]

Sounds like the perfect ammunition I need to argue back.  Thank you!

[Geert Bellekens]

I came across this question a few years ago myself, thinking that maybe there was a bug in EA that I needed to report.
After investigating the UML specs I came to the same conclusion as Simon. Sequence diagrams are apparently the exception where instances are not underlined.

I still think, for the sake of consistency, that they (OMG) should change the UML specs so that instances are underlined in all diagrams.

Geert

[qwerty]

Actually there is a feedback page for Superstructures somewhere at OMG. I used it some time ago but nothing happened. It turned out that it "fell under the table" as we say in Germany. Maybe Sparx could step in a put this topic on the table (so it doesn't fall under once again).

q.