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umlenterprise-architect

Can I create a nested activity diagram in UML?

For eg: I have an activity diagram depicting the flow of an API. Now that API calls an internal/static function. So, is it possible to depict the called function activity diagram with the caller activity diagram?

Solution

  • There are a couple of ways to achieve nesting in EA. One would be to create an Activity for the sub-process and invoke that.

    You can nest the actions in an activity and use that in the main flow as invocation (when dragging the Activity on the diagram use as "Invocation" rather than as "Link"). It then looks like

    enter image description here

    From the browser (well, it's EA) you can choose Add/Composite Structure Diagram. Here you can layout the subprocess (e.g. like)

    enter image description here

    When you double click the invocation it will open this structure diagram.

    Additionally you can use this diagram and drag it onto the (enlarged) invocation so it would show its guts:

    enter image description here

    The way it's shown in uml-diagrams.org is not possible for the diagram representation in EA (or I don't know how to do that). However, you can add ObjectNodes to Activities from the browser's Add context menu. These can be use in the referenced way.