/**
* @param SimpleXMLElement $xml
* @param StateMachine $sm
* @return static
*/
public static function fromXml(SimpleXMLElement $xml, StateMachine $sm)
{
$rVal = new static();
// Attach the statemachine
$rVal->sm = $sm;
// Value and Label
$rVal->value = (string) $xml->attributes()->value;
$rVal->label = (string) $xml->attributes()->label;
// Load events
foreach ($xml->event as $eventXml) {
$rVal->events[] = Event::fromXml($eventXml, $sm, $rVal);
}
// Load timeouts
foreach ($xml->timeout as $timeoutXml) {
$rVal->timeouts[] = Timeout::fromXml($timeoutXml, $sm, $rVal);
}
// Enter Commands XML fragments
$enterXml = !empty($xml->enter) ? $xml->enter[0]->command : [];
foreach ($enterXml as $item) {
$rVal->enter[] = $item;
}
// Exit Commands XML fragments
$exitXml = !empty($xml->exit) ? $xml->exit[0]->command : [];
foreach ($exitXml as $item) {
$rVal->exit[] = $item;
}
$rVal->isInitial = $sm->getInitialStateValue() === $rVal->value;
$rVal->isFinal = empty($rVal->events);
return $rVal;
}
/**
* @param StateMachineEvent $event
* @param StateMachineContext $context
* @return bool
* @throws Exception
* @throws \yii\db\Exception
*/
public function transition(StateMachineEvent $event, StateMachineContext $context)
{
// Let the context know which event triggered the transition
$context->setEvent($event);
/** @var yii\db\Transaction|false $txn */
$txn = $this->useTransactions ? $context->getModel()->getDb()->beginTransaction() : false;
try {
// Leaving current state...
foreach ($event->getState()->getExitCommands() as $command) {
if (!$command->execute($context)) {
$txn && $txn->rollBack();
return false;
}
}
// Cleanup old timeouts
Timeout::cleanUp($context);
// Entering new state...
$context->getModel()->{$context->getAttr()} = $event->getTarget();
foreach ($event->getTargetState()->getEnterCommands() as $command) {
if (!$command->execute($context)) {
$txn && $txn->rollBack();
return false;
}
}
// Register the new timeouts
foreach ($event->getTargetState()->getTimeOuts() as $timeout) {
$timeout->register($context);
}
// Persist the context's model data
$context->getModel()->save();
// Update Journal - if applicable
if ($this->modelJournal) {
$journal = $this->modelJournal;
/** @var StateMachineJournal $journal */
$journal::nu($context, $event);
}
$txn && $txn->commit();
// transition completed successfully
return true;
} catch (Exception $e) {
$txn && $txn->rollBack();
$context->attachException($e);
throw $e;
}
}