Domain Model; kinda

[Dee]

Hello,

I'm new to EA, and am trying to do a basic non-technical version of a domain model, where I visually represent domains and their variables, and their relationship to each other.

I'm using model UML with a domain model. I've created several packages, each with their classes. Some classes are 'shared' by other packages, which I've done by creating a link (and have experimented by creating an instance of the class). The issue I have is that when I create the overall domain model - I've dragged the packages onto the canvas for the domain model - the classes that are shared in the packages appear with no name. So all I see is a class icon with a pink top, but no name. What do I need to do to make the name appear? All of them are currently public, so that doesn't work. Is there a better way to 'share' classes amongst the packages?

Help! Will be eternally grateful

Cheers
Dee

[KP]

So all I see is a class icon with a pink top, but no name.

That's not a class, it's an object. You need to be careful when dragging a class from the project browser onto a diagram. Try this: Ctrl+Drag a class from the project browser onto a diagram and a dialog will appear asking you whether to create a simple link or an instance. Choose "as Simple Link", and also make sure that the following checkboxes are set: "Set Selection as Default for All Drag and Drop" and "Only show this dialog when Ctrl+Mouse drag is used". I'm afraid you will need to go through your diagrams and replace the (red-topped) object instances with simple links.

[Dee]

Hello, thanks for you prompt response!

If I drag as a 'simple link' as opposed to a 'instance', the item does not appear under the project tree.

How can I make it appear under the package tree when I drag something from a different package?

Or is there a better way to do what I am try to do?

Regards,
Dee

[RoyC]

A simple link does not create another element; it really is sharing that one element wherever it might live. Or, to put it another way, the simple link shows that one element has a role in more than one structure, as depicted in the diagrams. An instance, on the other hand, shows that one element is a general base definition for one or more other, more specific elements; for example, a Car Class is a general definition that is made more specific in the object elements 'Ford Falcon' and 'Holden Commodore'.

A package is just a convenient place to house elements, to help you identify what they are and to help you find them more easily. You can make a case for holding any specific element in any package, or for shoving your entire model into one package, but your element can't live in two packages at the same time.

And a diagram is just a photograph of what an element is doing within a certain context - sort of "this is me getting connected with some of my Use Case mates from Package X; oh, and this is me getting the low-down from a couple of heavy-heavy Requirements!"