A State instance can (and should) be shared by multiple Transition
objects when it is the same State for their origin/from State.
A State can be a regex state (or negated regex).
A regex state can be used in a transition and when added to a
statemachine the regular expression will be matched on all currently
known states on that statemachine and new Transitions will be added
to the statemachine that match the from/to state regexes. This is very
useful to build a lot of transitions very quickly.
to build a full mesh of transitions (all states to all states):
$a = new State('a');
$b = new State('b');
$c = new State('c');
$machine->addState($a);
$machine->addState($b);
$machine->addState($c);
$state_regex_all = new State('regex:|.*|');
$machine->addTransition(new Transition($state_regex_all, $state_regex_all));
protected function createLoader()
{
//we use the array loader
//in a non-example situation we would use a backend like a
//database for example
//@see PDO adapter and loader
//define the states
$new = new State('new', State::TYPE_INITIAL);
$green = new State('green', State::TYPE_NORMAL, State::COMMAND_NULL);
$orange = new State('orange', State::TYPE_NORMAL);
$red = new State('red', State::TYPE_NORMAL);
//create the transtions by using the states
$ng = new Transition($new, $green, 'go-green', Transition::RULE_TRUE, Transition::COMMAND_NULL);
$go = new Transition($green, $orange, 'go-orange', 'izzum\\examples\\trafficlight\\rules\\CanSwitch', 'izzum\\examples\\trafficlight\\command\\SwitchOrange');
$or = new Transition($orange, $red, 'go-red', 'izzum\\examples\\trafficlight\\rules\\CanSwitch', 'izzum\\examples\\trafficlight\\command\\SwitchRed');
$rg = new Transition($red, $green, 'go-green', 'izzum\\examples\\trafficlight\\rules\\CanSwitch', 'izzum\\examples\\trafficlight\\command\\SwitchGreen');
//set some descriptions for uml generation
$ng->setDescription("from green to orange. use the switch to orange command");
$go->setDescription("from new to green. this will start the cycle");
$or->setDescription("from orange to red. use the appropriate command");
$rg->setDescription("from red back to green.");
$new->setDescription('the init state');
$green->setDescription("go!");
$orange->setDescription("looks like a shade of green...");
$red->setDescription('stop');
$transitions[] = $ng;
$transitions[] = $go;
$transitions[] = $or;
$transitions[] = $rg;
$loader = new LoaderArray($transitions);
return $loader;
}
/**
* sets the state as the current state and on the backend.
* This should only be done:
* - initially, right after a machine has been created, to set it in a
* certain state if the state has not been persisted before.
* - when changing context (since this resets the current state) via
* $machine->setState($machine->getCurrentState())
*
* This method allows you to bypass the transition guards and the transition
* logic. no exit/entry/transition logic will be performed
*
* @param State $state
* @param string $message optional message. this can be used by the persistence adapter
* to be part of the transition history to provide extra information about the transition.
* @throws Exception in case the state is not valid/known for this machine
*/
public function setState(State $state, $message = null)
{
if ($this->getState($state->getName()) === null) {
throw new Exception(sprintf("%s state '%s' not known to this machine", $this->toString(), $state->getName()), Exception::SM_UNKNOWN_STATE);
}
//get the state known to this machine so we are sure we have the correct reference
//even if the client provides another instance of State with the same name
$state = $this->getState($state->getName());
$this->getContext()->setState($state->getName(), $message);
$this->state = $state;
}
/**
* does an input regex state match a target states' name?
*
* @param State $regex
* the regex state
* @param State $target
* the state to match the regular expression to
* @return boolean
* @link https://php.net/manual/en/function.preg-match.php
* @link http://regexr.com/ for trying out regular expressions
*/
public static function matchesRegex(State $regex, State $target)
{
$matches = false;
if ($regex->isNormalRegex()) {
$expression = str_replace(State::REGEX_PREFIX, '', $regex->getName());
$matches = preg_match($expression, $target->getName()) === 1;
}
if ($regex->isNegatedRegex()) {
$expression = str_replace(State::REGEX_PREFIX_NEGATED, '', $regex->getName());
$matches = preg_match($expression, $target->getName()) !== 1;
}
return $matches;
}
/**
* {@inheritDoc}
*/
public function load(StateMachine $stateMachine)
{
//decode the json in a php object structure
$decoded = yaml_parse($this->getYaml(), false);
//yaml decoding returns a php array.
$name = $stateMachine->getContext()->getMachine();
$found = false;
$data = null;
if (is_array(@$decoded['machines'])) {
foreach ($decoded['machines'] as $data) {
if ($data['name'] === $name) {
$found = true;
break;
}
}
}
if (!$found) {
//no name match found
throw new Exception(sprintf('no machine data found for "%s" in yaml. seems like a wrong configuration.', $name), Exception::BAD_LOADERDATA);
}
//accessing an array with an @ error suppresion operator ('shut the f**k up' operator),
//allows you to get properties, even if they do not exist, without notices.
//this lets us be a little lazy in mapping the array properties to the state and transition properties
$states = array();
foreach ($data['states'] as $state) {
$tmp = new State($state['name'], $state['type'], @$state['entry_command'], @$state['exit_command'], @$state['entry_callable'], @$state['exit_callable']);
$tmp->setDescription(@$state['description']);
$states[$tmp->getName()] = $tmp;
}
$transitions = array();
foreach ($data['transitions'] as $transition) {
$tmp = new Transition($states[$transition['state_from']], $states[$transition['state_to']], @$transition['event'], @$transition['rule'], @$transition['command'], @$transition['guard_callable'], @$transition['transition_callable']);
$tmp->setDescription(@$transition['description']);
$transitions[] = $tmp;
}
//delegate to loader
$loader = new LoaderArray($transitions);
return $loader->load($stateMachine);
}
/**
* gets all data for transitions.
* This method is public for testing purposes
*
* @param string $machine
* the machine name
* @return Transition[]
*/
public function getLoaderData($machine)
{
$rows = $this->getTransitions($machine);
$output = array();
// array for local caching of states
$states = array();
foreach ($rows as $row) {
$state_from = $row['state_from'];
$state_to = $row['state_to'];
// create the 'from' state
if (isset($states[$state_from])) {
$from = $states[$state_from];
} else {
$from = new State($row['state_from'], $row['state_from_type'], $row['state_from_entry_command'], $row['state_from_exit_command']);
$from->setDescription($row['state_from_description']);
}
// cache the 'from' state for the next iterations
$states[$from->getName()] = $from;
// create the 'to' state
if (isset($states[$state_to])) {
$to = $states[$state_to];
} else {
$to = new State($row['state_to'], $row['state_to_type'], $row['state_to_entry_command'], $row['state_to_exit_command']);
$to->setDescription($row['state_to_description']);
}
// cache to 'to' state for the next iterations
$states[$to->getName()] = $to;
// build the transition
$transition = new Transition($from, $to, $row['event'], $row['rule'], $row['command']);
$transition->setDescription($row['transition_description']);
$output[] = $transition;
}
return $output;
}
/**
* @test
* @group regex
*/
public function shouldReturnArrayOfMatchedStates()
{
$a = new State('a');
$b = new State('ab');
$c = new State('ba');
$d = new State('abracadabra');
$e = new State('action-hero');
$f = new State('action-bad-guy');
$g = new State('ac');
$targets = array($a, $b, $c, $d, $e, $f, $g);
$regex = new State('regex:/.*/');
$this->assertEquals($targets, Utils::getAllRegexMatchingStates($regex, $targets));
$regex = new State('regex:/^a.*/');
$this->assertEquals(array($a, $b, $d, $e, $f, $g), Utils::getAllRegexMatchingStates($regex, $targets));
$regex = new State('regex:/^a.+/');
$this->assertEquals(array($b, $d, $e, $f, $g), Utils::getAllRegexMatchingStates($regex, $targets));
$regex = new State('regex:/^a.*a.+$/');
$this->assertEquals(array($d, $f), Utils::getAllRegexMatchingStates($regex, $targets));
$regex = new State('regex:/^ac.*-.+$/');
$this->assertEquals(array($e, $f), Utils::getAllRegexMatchingStates($regex, $targets));
$regex = new State('ac');
$this->assertFalse($regex->isRegex());
$this->assertEquals(array($g), Utils::getAllRegexMatchingStates($regex, $targets), 'non regex state');
}
/**
* @test
* @group regex
*/
public function shouldNotReturnRegexState()
{
$name = 'rege:.*';
$regex = new State($name);
$this->assertFalse($regex->isRegex());
$this->assertFalse($regex->isNormalRegex());
$this->assertFalse($regex->isNegatedRegex());
}
/**
* {@inheritDoc}
*/
public function load(StateMachine $stateMachine)
{
//load the xml in a php object structure. suppres warning with @ operator since we explicitely check the return value
$xml = @simplexml_load_string($this->getXML());
if ($xml === false) {
//could not load
throw new Exception(sprintf('could not load xml data. check the xml format'), Exception::BAD_LOADERDATA);
}
$name = $stateMachine->getContext()->getMachine();
$found = false;
$data = null;
foreach ($xml->machine as $data) {
if ((string) @$data->name === $name) {
$found = true;
break;
}
}
if (!$found) {
//no name match found
throw new Exception(sprintf('no machine data found for %s in xml. seems like a wrong configuration.', $name), Exception::BAD_LOADERDATA);
}
//accessing xml as an object with the @ error suppresion operator ('shut the f**k up' operator)
//allows you to get properties, even if they do not exist, without notices.
//this let's us be a littlebit lazy since we know some nonessential properties could not be there
$states = array();
foreach ($data->states->state as $state) {
$tmp = new State((string) $state->name, (string) $state->type, (string) @$state->entry_command, (string) @$state->exit_command, (string) @$state->entry_callable, (string) @$state->exit_callable);
$tmp->setDescription((string) @$state->description);
$states[$tmp->getName()] = $tmp;
}
$transitions = array();
foreach ($data->transitions->transition as $transition) {
$tmp = new Transition($states[(string) @$transition->state_from], $states[(string) @$transition->state_to], (string) @$transition->event, (string) @$transition->rule, (string) @$transition->command, (string) @$transition->guard_callable, (string) @$transition->transition_callable);
$tmp->setDescription((string) @$transition->description);
$transitions[] = $tmp;
}
//delegate to loader
$loader = new LoaderArray($transitions);
return $loader->load($stateMachine);
}
/**
* {@inheritDoc}
*/
public function load(StateMachine $stateMachine)
{
//decode the json in a php object structure
$decoded = json_decode($this->getJSON(), false);
if (!$decoded) {
//could not decode (make sure that fully qualified names are escaped with
//2 backslashes: \\izzum\\commands\\Null and that only double quotes are used.
throw new Exception(sprintf('could not decode json data. did you only use double quotes? check the json format against %s', 'http://jsonlint.com/'), Exception::BAD_LOADERDATA);
}
$name = $stateMachine->getContext()->getMachine();
$found = false;
if (is_array(@$decoded->machines)) {
foreach ($decoded->machines as $data) {
if ($data->name === $name) {
$found = true;
break;
}
}
}
if (!$found) {
//no name match found
throw new Exception(sprintf('no machine data found for %s in json. seems like a wrong configuration.', $name), Exception::BAD_LOADERDATA);
}
//accessing json as an object with an @ error suppresion operator ('shut the f**k up' operator),
//allows you to get properties, even if they do not exist, without notices.
//this lets us be a little lazy in mapping the json properties to the state and transition properties
$states = array();
foreach ($data->states as $state) {
$tmp = new State($state->name, $state->type, @$state->entry_command, @$state->exit_command, @$state->entry_callable, @$state->exit_callable);
$tmp->setDescription(@$state->description);
$states[$tmp->getName()] = $tmp;
}
$transitions = array();
foreach ($data->transitions as $transition) {
$tmp = new Transition($states[$transition->state_from], $states[$transition->state_to], @$transition->event, @$transition->rule, @$transition->command, @$transition->guard_callable, @$transition->transition_callable);
$tmp->setDescription(@$transition->description);
$transitions[] = $tmp;
}
//delegate to loader
$loader = new LoaderArray($transitions);
return $loader->load($stateMachine);
}
/**
*
* @param State $state_from
* @param State $state_to
* @param string $event
* optional: an event name by which this transition can be
* triggered
* @param string $rule
* optional: one or more fully qualified Rule (sub)class name(s)
* to check to see if we are allowed to transition.
* This can actually be a ',' seperated string of multiple rules
* that will be applied as a chained 'and' rule.
* @param string $command
* optional: one or more fully qualified Command (sub)class
* name(s) to execute for a transition.
* This can actually be a ',' seperated string of multiple
* commands that will be executed as a composite.
* @param callable $callable_guard
* optional: a php callable to call. eg: "function(){echo 'closure called';};"
* @param callable $callable_transition
* optional: a php callable to call. eg: "izzum\MyClass::myStaticMethod"
*/
public function __construct(State $state_from, State $state_to, $event = null, $rule = self::RULE_EMPTY, $command = self::COMMAND_EMPTY, $callable_guard = self::CALLABLE_NULL, $callable_transition = self::CALLABLE_NULL)
{
$this->state_from = $state_from;
$this->state_to = $state_to;
$this->setRuleName($rule);
$this->setCommandName($command);
$this->setGuardCallable($callable_guard);
$this->setTransitionCallable($callable_transition);
// setup bidirectional relationship with state this transition
// originates from. only if it's not a regex or final state type
if (!$state_from->isRegex() && !$state_from->isFinal()) {
$state_from->addTransition($this);
}
// set and sanitize event name
$this->setEvent($event);
}
/**
* @test
*/
public function shouldHaveBidirectionalAssociation()
{
$from = new State('a');
$to = new State('b');
$transition = new Transition($from, $to);
$this->assertTrue($from->hasTransition($transition->getName()));
$this->assertFalse($to->hasTransition($transition->getName()), 'not on an incoming transition');
}
