Possibility to add diagrams to a method

[Jeronimo]

I miss the possibility to add a activity or state chart to a method in a Class diagram. It would be helpful to document a algorithm of a method with a activity diagram, so it would be possible to open the activity diagram by double clicking the method.

[Geert Bellekens]

Jeronimo,

Attributes and Operations cannot own anything which is displayed on such activity or state diagram, that's probably the reason why you can't nest a diagram under an Attribute or Operation.
What you can do is define an Activity, State machine, or Interaction and link that to the Operation using the Behavior tab.
Activities, State Machines or Interactions (or other Behaviors) can own the elements shown on such a diagram, so, from a UML point of view, you then have a syntactically correct model.

Geert