On Wed, Apr 8, 2009 at 7:53 AM, Anna Södling <[email protected]> wrote: > Hello, > > I'm having a little problem regarding timers in SCXML. I have built a > simple statemachine with two states and a transition going from each > state to the other. The transitions should not be taken when a user > "orders" an event, but when a timer has timed out. The code I have > written for this (which obviously is incorrect since it doesn't solve my > problem, but it might give an idea of how I'm thinking) looks like this > (I've tried to implement the timers like in the examples on this page, > if that might be any hint to what may be wrong: > http://www.ling.gu.se/~lager/Labs/SCXML-Lab/ ): > > <scxml version="1.0" initialstate="167" xmlns:cs=" > http://commons.apache.org/scxml"; xmlns=" > http://www.w3.org/2005/07/scxml";> > <state id = "167"> > <transition target="StateA"/> > </state> > <state id ="StateA"> > <onentry> > <send sendid="1" target="'StateA'" event="'ToB'" delay="'1000ms'" /> > </onentry> > <transition event="ToB" target="StateB"/> > </state> > <state id="StateB"> > <onentry> > <send sendid="2" target="'StateB'" event="'ToA'" delay="'2000ms'" /> > </onentry> > <transition event="ToA" target="StateA"/> > </state> > </scxml> > > I get complaints about my target and event parts. What I want is that > when you enter a state, a timer with the value of the delay attribute > should start ticking inside the current state and when the timer times > out, it should take the transition with the same event as the event in > the send tag. But when I do this, I get this warning: > VARNING: <send>: target expression "StateA" evaluated to null or empty > String > (I tried to write target="'Self'" instead, too, but that didn't help > either) > <snip/>
Targets cannot be states, only entire state machines. "Self" has no associated semantics at all in SCXML. > I also tried to remove the target attribute, but then I get this line: <snap/> Thats the right way to proceed. No target means current state machine. > INFO: send ( sendId: 1, target: null, targetType: scxml, event: ToB, > params: null, hints: null, delay: 1000) > and nothing else happens. > > If anyone has any ideas of what I might have done wrong and how I can > solve this problem (preferably without implementing any custom actions), > I would be really happy! > <snip/> Use an EventDispatcher that supports timers. Here is one that uses Java SE timers: http://commons.apache.org/scxml/apidocs/org/apache/commons/scxml/env/SimpleScheduler.html So, along these lines: SCXMLExecutor exec = new SCXMLExecutor(); ... exec.setEventDispatcher(new SimpleScheduler(exec)); ... -Rahul > Sincerely, > Anna > > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
