On Tue, Jun 21, 2011 at 3:42 PM, Artem Vovk <vovk.ar...@googlemail.com> wrote: > Can I use dynamic transition targets? Something like this? > > <datamodel> > <data id="dyn_state" expr="State1"> > </datamodel> > > ... > > <transition ... target="dyn_state"/> > > If I use it on this way, I receive an exception: Transition target with ID > "dyn_state" not found -> Interpreter thinks that it is a name of the state, > but not the variable... Is there a way to define such transitions? > <snip/>
Not directly as you are illustrating above. Most state machines in general, and SCXML in particular, requires you specify fixed target(s) for each transition. This is actually quite useful because it allows static analysis to determine whether all transition targets are legal even before the state machine is executed. It is also not as limiting as it may seem at first, because of the existence of things like guard conditions on transitions and history states. For the above, a literal translation may appear to be as follows (replacing dynamic target with static ones): <transition cond="dyn_state eq 'State1'" target="State1"/> <transition cond="dyn_state eq 'State2'" target="State2"/> ... The above pattern can certainly be used, and may seem more verbose. But note that there are usually two <assign> or similar statements elsewhere that are updating the data 'dyn_state'. Often, these can instead be replaced as appropriate guard conditions on the two transitions above so the net effect is no change in verbosity. -Rahul --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@commons.apache.org For additional commands, e-mail: user-h...@commons.apache.org
