From: Andreas Huber (ahd6974-spamgroupstrap_at_[hidden])
Date: 2005-03-02 04:53:57
Hi Jan
> I realized a weird behaviour when using boost::fsm.
> Here's my state setup:
>
> I have a parent state which has two substates. One is basicly a noop as
> InnerInitial, the other is and OptionsDialog.
> Now, in a custom_reaction's react function in the parent state, I call
> transit<OptionsDialog> in order to go to the OptionsDialog-substate.
> What happens is that the parentstate itself is destroyed and reentered,
> then it enters the OptionsDialog state.
As Darryl has already pointed out (Thanks Darryl!) this is expected and in
line with the behavior defined by UML/Harel.
> Something similar happens when I use transit<ParentState> to go back to
> the ParentState (which should automatically enter the InnerInitial,
> no?).
Yes.
> It exits the OptionsDialog, then exits ParentState and reenters
> ParentState (I haven't checked if it enters the InnerInitial).
Again, all expected and it should enter InnerInitial.
> If in the OptionsDialog, I do a transit<NoOpInnerInitial> it just goes
> there without first destroying the parent-state (just exits
> OptionsDialog but not ParentState).
> Is this the expected behaviour, if so, could someone explain how to get
> the desired behaviour?
IIUC, it seems that you don't need the parent state, as you basically just
have 2 states (ShowOptionsDialog/DontShowOptionsDialog), with 2 or 3
transitions between these states. Then again, this obviously depends on
whether it is just a toy example or a part of a bigger FSM. In the latter case
you'd need to give a rough description of the desired behavior of the whole
FSM...
Regards,
Andreas