Reorder Transitions

In a state diagram, if a state has multiple transitions leaving it then these need to be evaluated in a set order to ensure program execution is expected and repeatable.

For example, if two transitions leave a state both evaluate to “true”, we need to ensure one of the transitions has priority over the other.

When a state with multiple exit transitions is selected, the order of transition evaluation is displayed, where “1” shows the first transition to be evaluated.

This transition order is also shown if a transition is selected. A state with only one transition leaving it will not show the transition order.

The order can be set on the diagram itself by reconnecting the transitions to the state (the last transition to be connected will have the lowest priority).

Alternatively, the transitions can be reordered by editing the properties of the state icon and clicking “Set transition order” to open the Transition Order dialog.

When using the Transition Order dialog, the applicable transitions are listed using either their name, condition or function.

Highlighting a transition and pressing the up/down arrows will move it higher/lower in the transition order.

The transition at the top of the list will be evaluated first. When transitions are evaluated, the evaluation process stops once a transition has evaluated to true.

All other transitions leaving the state are assumed to be false even if they have not been evaluated yet.