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From Woonsan Ko <>
Subject Re: [SCXML] How to obtain a collection of valid events
Date Mon, 23 May 2016 19:01:48 GMT
On Fri, May 20, 2016 at 9:36 PM, Mansour Al Akeel
<> wrote:
> Woonsan,
> Thank you for replying.
> From what you said, I can conclude that this is not supported or
> offered by SCXML. Am I right here?
If you mean finding available event names/patterns (see 3.12.1 in for a transition, there seems to
be no convenient method unless you implement a utility method by
yourself based on SCXMLSemanticsImpl.
But, basically the specification is more complex than your simple use
case. I guess that's why there has been no convenient utility yet.

> AFAIR an FSM should report if the token is recognized or not, and not
> just complete the transition/ignore the token silently.. If I am right
> here as well, then this use case is not specific to me.
Error reporting is a bit different from your use case, in my view.
I'm not really sure that SCXMLExecutor should report an error at the
moment when it cannot find any transition associated. I couldn't find
anything clear about that in the specification. If you find something,
please let us know. ;-)

> Do you see in the future, this will be supported by SCXML ? Should we
> open a JIRA ticket ?
commons-scxml has org.apache.commons.scxml2.ErrorReporter interface
which can be set through
Again, I'm not really sure it has to report an error when not finding
a transition to proceed on an event. It doesn't sound like an error to
me, but maybe a warning in that case.
What do others think?



> Thank you
> On Mon, May 16, 2016 at 10:04 AM, Woonsan Ko <> wrote:
>> Hi Mansour,
>> I don't see any convenient method to easily figure out what are
>> available event names for transitions like your use case needs.
>> All the knowledge about that is encapsulated in
>> org.apache.commons.scxml2.semantics.SCXMLSemanticsImpl internally, so
>> you might want to take a look at it. SCXMLSemantics is not exposed to
>> applications from the execution context.
>> Regards,
>> Woonsan
>> On Sat, May 14, 2016 at 9:19 AM, Mansour Al Akeel
>> <> wrote:
>>> Hello all,
>>> Based on my understanding, a state machine provides feedback about the
>>> input. If the token is not recognized, it should report this.
>>> I am prototyping in SCXML, and trying to find a way to find if the
>>> supplied event/token is recognized or not. I am unable to find a way
>>> to tell. May be someone else had luck with this, and can share the way
>>> with me.
>>> So my question is, I am working in an AbstractStateMachine, and I have
>>> an instance of SCXMLExcutor obtained from getEngine(). How can I find
>>> the valid inputs ??
>>> Thank you
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