Standards families
UML state machine — pseudostates and composite states
States, transitions with triggers/guards/effects, plus the full pseudostate vocabulary: initial, choice, junction, history, entry/exit points.
uml.statemachine@1New DDN source
Why use it?
State machines make "what may happen next" enumerable — reviewers can ask about every missing transition.
When it helps
Lifecycle-heavy objects: orders, connections, approvals, devices.
How to read it
- Rounded boxes are states; arrows are transitions labelled trigger [guard] / effect.
- Filled circles and diamonds are pseudostates — routing, not resting places.
What you need
- The states
- The events that drive transitions
- Guards and effects
Things to check
- Do not leave a state with no path out unless it is final by intent.
- Do not put work in a pseudostate — effects belong on transitions.
Scope of this diagram
Declared machine with well-formedness validation; no code execution or model checking is claimed.
Work with the converted example
- Open the viewer and select
pseudostates. Inspect the rendered view and its source. - Open the designer. Keep the selected profile and inspect its legal palette and property controls.
- Change one displayed title or an appropriate data value. Apply the edit and check the resulting diagram.
- Run the verifier and review its diagnostics before moving complete content into review.
- Download your edited DDN source to retain the change.
The example uses the indentation-based ddn-next-1 dialect. The language guide explains reusable definitions, dotted data rows and explicit property blocks.