Inserting Messages in Sequence Diagrams

[olav]

Hi!

I just tried to update a sequence diagram of an existing model. The issue is to insert some messages somewhere in between. Unfortunately, I failed miserably...

It seems to me that it's only possibly to append new messages to the end of a sequence diagram, but I hardly can believe this to be true. Could anybody give a hint about how to do that if that's possible at all?


Cheers,

Olav

[sargasso]

Use menu Diagram | Sequence Communications Messages.

BUT build a test diagram first and muck around to get the gist of how it works.

bruce

[olav]

Hi!

Thanks for the instantaneous reply! It's funny, but today I can insert messages in between without having to access the menu as you hinted me to do.

Anyway, even if I would want to 'Sequence Communication Messages' the menu item stays always ghosted in EA. What's wrong?

The sequence diagram uses 'untyped' objects, i.e. I did not specify a class for the lifelines. Is that what keeps the menu item from being enabled?

Anyway, struggling for as much help as possible I have another related question: When I insert another diagram as a 'diagram reference' into the sequence diagram it sticks always to the top. However, I would like to move the frame down a bit in order to place it around those messages that are being modelled more precisely in the referenced diagram.

When I insert a diagram reference into a class diagram it works as desired. That's what I did yesterday: I created a class diagram, drew a sequence diagram in there and tried to insert messages somewhere in between. I know this sounds crazy (it is crazy actually, I gather), but I made progress - at least until I wanted to insert messages somewhere in between.

So my 'formal' requirement is: I want to draw a top-level sequence diagram that references more detailed sequence diagrams. I want to be able to navigate between the different layers of abstraction by means of (double-)clicking on certain diagram elements.

Is my approach completly off-roads? Could you or somebody else give me a hint or two, please?

Thank you very much!


Cheers,

Olav

[TrtnJohn]

Sequence Communications Messages is for Communications Diagrams NOT Sequence Diagrams.  You can just drag the messages around in sequence diagrams to re-order them.

[sargasso]

  That'll teach me not to read the question properly and just assume that it's related to one of my pet bugs.

bruce


Olav,  re your other questions.  I think you'll need to review how the z-order of the things in the diagram affect what you're trying to do.

[olav]

Sargasso!

Thanks for being that responsive!

I just wonder how you come up with the idea of z-ordering being of help to my efforts... Possibly my English is too cryptic after all... Or I am indeed completely off the track...

When I talk about layers of abstraction I do not mean different layers shown in a single diagram. More so I structured the overall modelling problem according to distinct layers of abstraction and want to display one single layer per diagram. Talking about sequence diagrams there are messages on a high level of abstraction that involve quite a few activities in detail. Think for example about a HTTP-Request that may be shown as a single message between the browser and server (high-level) OR numerous tiny messages between all the involved machines en route from the machine the browser is running on and the server machine (low-level).

Assuming that the word 'layer' caused you to hint at z-ordering I furtherly assume that we have a classic misunderstanding, right? I hope that the clarification above is indeed that and here I am trying to rephrase my question:

In order to link a single message of a sequence diagram to another diagram depicting the gory details of that particular high-level message, I gathered using diagram references framing the high-level message in question would be a good idea. However, in a 'real' sequence diagram (i.e. a diagram created as of type 'sequence') it is seemingly impossible to drag a diagram reference off the top of the diagram. I can only drag it to the left or right, but unfortunately not to the bottom.

Is referencing a diagram this way actually a bad idea? Is there in general a good way of linking diagrams to single elements of other diagrams?

Thank you so much for your time&effort!


Cheers,

Olav

[mikewhit]

Looking in Douglass's Real Time UML book, I see that he frequently uses Packages to wrap up functional layers.

Perhaps you could get some mileage out of that ?

[DanInOttawa]

Well, I have read these posts and I seem to have a common problem. I cannot add new messages 'in-between' exiting messages in my sequence diagram. Adding a new message simply puts it at he bottom of my diagram, and dragging it dows not allow me to bring it above the last message in the diagram.

Am I missing something?

Daniel

[KP]

Well, I have read these posts and I seem to have a common problem. I cannot add new messages 'in-between' exiting messages in my sequence diagram. Adding a new message simply puts it at he bottom of my diagram, and dragging it dows not allow me to bring it above the last message in the diagram.

Am I missing something?

Daniel

First thing to check is: is it really a sequence diagram? If you put sequence lifelines on a class diagram then it won't work. Easiest way to check is "Diagram | Change Diagram Type" and see which option is currently selected.

HTH

[olav]

That's it!

In true sequence diagrams I am perfectly able to re-arrange the messages as I like.

In class diagrams I can drag diagram reference frames across the whole diagram (even y-dimensional) in order to make them frame that part of the diagram I want to.

There is no type of diagram that allows for both features (sequencing messages and framing diagram elements not at the top of the diagram), right?

Hence: In general, how can I link diagram elements (like messages) to diagrams the way that when I click (double-click or whatever-click) on it the referenced diagrams pops up? Is there a way to achieve this?

Thank you once more!


Cheers, Olav