UML dependency relationship - should I use it here?

Question

If I have a class "Foo" that contains an instance of "Delegate". Foo delegates method calls to class "Delegate" like so:

public class Foo {
   private Delegate delegate = new Delegate();

   public void bar() {
      delegate.bar();
   }
}

When I draw the Foo class in UML, would it have a dependency relationship (dashed line with an arrowhead) between it and the Delegate class, or would it have a line representing a Composition relationship instead?

Answer 1

The nice thing about UML is that you have some leeway, but in your case, IMHO, dependency is better.

You don't have a delegate as a property of a Foo (there is no getDelegate) so no one looking at your system would really care that a Foo was composed of a delegate (among other things).

Then again, if your UML diagram was given to a tool that would generate code from a diagram, it might. :)

Do what feels right to the people (or agents) to whom you are giving the diagram.