The ‘wait’ expression simply blocks/waits until the given condition evaluates to true. This expression accepts a timeout (else it will block ad eternam).

    sequence do
        wait :until => "${done} == true"
        participant :toto
    end

Participant ‘toto’ will receive a workitem after the variable ‘done’ is set to true (somewhere else in the process definition).

    sequence do
        wait :runtil => "Time.new.to_i % 7 == 0"
        participant :toto
    end

Participant ‘toto’ will receive a workitem after a certain condition expressed directly in Ruby evaluates to true.

‘wait’ is different than ‘when’ : when it times out (if a timeout is set, the wait ceases and the flow resumes. On a timeout, ‘when’ will not execute its nested ‘consequence’ child.