Re: adding connection points to UML class diagrams?

[Alexander <RittervomNie web de>]

Tim Olsen schrieb:
> [...] so that
> the line from D to B does not touch the line from C to B--otherwise it
> might look like D is also a subclass of A.

When I create classes in my version of Dia (0.94) they have connection 
points at least at every corner and in the middle. So I'm able to connect 3 
associations to the bottom or top of each class and another to each side:

+------+------+
|    Class    |
+-------------+
|-------------|
+-------------+
Sample class, methods and attributes visible, '+' marks a connection point

> However, there is no option to add a connection point to the class
> diagram.  Any recommendations on what I should do?
Use the right 'class'-element, update your dia or describe the problem more 
detailed *g*.

Additionally to your lack of connection points I want to write some warning 
note: Avoid the usage of "multiple inheritance" and replace it with 
interfaces. Often "multiple inheritance" leads to a bad model melting 
together "roles" which should better stay apart from each other. For 
example a gui element (maybe a Button-class) should never become a business 
element (being able to perform some operation when pressed). Also gui 
elements should stay clean (melting together a list and a button makes no 
sense, use combo-boxes instead). With an interface your shure when it comes 
to casting. Mulitple inheritance can be quite confusing when using it as 
two different classes. Interfaces make it safe and clean. (If you don't 
have interfaces, use abstract classes being absolutely abstract, e.g. no 
method implementation. That's where you can use multiple inheritance to 
emulate the existance of interfaces)