Author image Barrie Slaymaker


StateML::Arc - A transition between states


An arc is a transition between states; they occur by default or on certain events.

A loopback arc is an arc that transits from a state back to itself.

Arcs can have handlers, either explicitly using one or more <handler>s or by reference to an <action> using an action-id attribute (we need to allow arcs to have multiple actions at some point).

Arcs can contain an <event>, in which case the <arc>'s event-id= is automatically read from the <event> (which in turn may omit it and let StateML::Machine assign one).

Default from/to state ids.

On parsing, <arc> elements may appear in <state> elements. When they do, the from= and/or to= attributes may be omitted; they will default to the parent state's id.

METHODS (incomplete, see the source, luke)


Returns the event for this arc, if set.


Returns the event_id if set. If not set (undef), returns the default event's ID if it is present in the machine. Note that "" is a not valid id.


Returns the name if set. If not set, returns the name of the event_id event (if that's set). Note that "" is a valid name.


Like StateML::Object::attribute, but inherits from the event.


Like StateML::Object::attributes, but inherits from all handlers and then the event.



    Copyright 2003, R. Barrie Slaymaker, Jr., All Rights Reserved


You may use this module under the terms of the BSD, Artistic, or GPL licenses, any version.


Barrie Slaymaker <>