On Tue, May 24, 2005 at 06:15:41PM -0500, Tim Klein wrote:
> As a result of a discussion here a few weeks ago (on March 30, in
> case you want to retrieve it from the archives), I learned that the
> 'options' parameter to POE::Session::create is not meant to be used
> for "custom" options. For example, the following, even though it may
> work, is not proper:
>
> POE::Session->create
> (
> inline_states => [...],
> options => { 'myname' => 'Tim' } <--- my custom option 'myname'
> );
>
> Instead, the proper way to pass custom parameters at session creation
> time is to use the 'heap' parameter or the 'args' parameter to the
> create() command.
>
> OK, so far so good. But what's the proper way to do the same thing
> when creating a POE::NFA instead of a POE::Session? The
> POE::NFA::spawn command doesn't have a 'heap' (or 'runstate')
> parameter or an 'args' parameter. The perldoc says "The spawn()
> method currently only accepts inline_states and options." So do I
> have to use 'options' after all?
POE::NFA is not well documented. It seems to be the strange cousin of
POE::Session that people rarely talk about, so time is focused
elsewhere.
The NFA session doesn't have a single _start event, so there's nowhere
for constructor parameters to go. And while it may have many states,
there's no initial state specified in spawn().
So the key to starting a state is partially documented in the
SYNOPSIS:
# Spawn an NFA and enter its initial state.
POE::NFA->spawn(
inline_states => \%states
)->goto_state( $start_state, $start_event );
That spawns a new POE::NFA instance, enters its initial state, and
fires off an event that notifies the session that the state has been
entered.
The next clue in this puzzle is goto_state() itself. Its third and
subsequent parameters are passed as arguments to the $start_event in
the state being entered.
I hope that helps.
--
Rocco Caputo - http://poe.perl.org/
