Re: [Boost-users] Statechart serialization

From: Andreas Huber (ahd6974-spamboostorgtrap_at_[hidden])
Date: 2007-08-08 18:06:11

Hi Lukasz

> I'm not sure i understand how this would work. If i use the serialization
> library, then i could serialize the current state (by inspecting the 
> current
> state configuration as you said). But what would happen to all the members
> of the parent class (for example "simple_state" ) since they don't support
> serialization ? Unless you meant to use some other serialization method ?

As long as you save all the custom members of the current innermost state 
and all its outer states *and* also save the class name of the current 
innermost state you have made persistent all information that is necessary 
to reconstitute exactly the same state during loading, see below.

> As for the "special transitions", i suppose i would need a sort of 
> "initial
> transition" per state that would allow me to go to it directly, right ?

Exactly.

> Also, if i have (and i sure will) state local storage, then i would need
> some way to restore its values, which i don't quite see how it would work
> using this approach (since i'm not re-creating the object using the one 
> that
> was restored but rather using the transition).

You'd first transit to the state (probably with a huge switch-case that 
takes a different transition based on the previously saved name) and then 
assign the saved values to the state-local members. You'd have a different 
load function for each innermost state. A lot of grunt work, but it's 
possible as long as your machine is non-orthogonal. Unfortunately, there's 
no way to do the same for machines with orthogonal regions.

HTH,

Andreas

> Andreas Huber-3 wrote:
>>
>>
>> For non-orthogonal machines, saving the state is relatively easily done 
>> by
>> inspecting the current state configuration with the public interface
>> (state_machine<>.state_begin() & state_machine<>.state_end()). Loading is
>> more
>> cumbersome as you need to be able to go to the previously stored state
>> after
>> initiation. The only way to do this at the moment is to introduce special
>> transitions.
>>
>>
>
> -- 
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> http://www.nabble.com/Statechart-serialization-tf4131326.html#a12058696
> Sent from the Boost - Users mailing list archive at Nabble.com.

-- 
Andreas Huber
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