In sequence diagrams, a guard condition contains an interaction
constraint. An interaction constraint is a condition or restriction.
A guard condition is created automatically when you create a combined
fragment. You can also manually add a guard condition to an interaction
operand that does not have an existing guard condition.
Before you begin
You must have a sequence diagram open that contains at least
one combined fragment with multiple lifelines.
Procedure
- In the diagram editor, right-click an interaction operand
that has no existing guard condition; then click .
- Click in the field, type the guard condition, and press
Enter.
What to do next
Note: In a loop combined fragment, you can edit
the guard condition using the textual syntax [ ‘(‘ <minint>
[, <maxint> ] ')' ], where minit and maxint are
non-negative integers, and state the minimum and maximum number of
times that a loop can occur.