/**
* Process a transition.
* `\Zhibaihe\State\MachineException` is thrown when:
* 1. the machine is not initialized;
* 2. no transition is defined at current state;
* 3. the transition is illegal at current state.
*
* @param string $transition The transition to be processed
* @param array $arguments The arguments for the transition
* @return void
*
* @throws \Zhibaihe\State\MachineException
*/
public function process($transition, $arguments = [])
{
if (!$this->ready()) {
throw new MachineException("Machine not initialized.");
}
if (!array_key_exists($this->state, $this->transitions)) {
throw new MachineException("No transitions defined for state '{$this->state}'.");
}
$transitions = $this->transitions[$this->state];
if (!array_key_exists($transition, $transitions)) {
throw new MachineException("Transition '{$transition}' at state '{$this->state}' is invalid.");
}
$to = $transitions[$transition];
if ($this->policy->denies($transition, $this->state, $to, $arguments)) {
return false;
}
$this->triggerWalkers($transition, $this->state, $to, $arguments);
$this->triggerListeners($transition, $this->state, $to, $arguments);
$this->state = $to;
return true;
}