Chris@14: <?php
Chris@14: 
Chris@14: /*
Chris@14:  * This file is part of the Symfony package.
Chris@14:  *
Chris@14:  * (c) Fabien Potencier <fabien@symfony.com>
Chris@14:  *
Chris@14:  * For the full copyright and license information, please view the LICENSE
Chris@14:  * file that was distributed with this source code.
Chris@14:  */
Chris@14: 
Chris@14: namespace Symfony\Component\DependencyInjection;
Chris@14: 
Chris@14: use Psr\Container\ContainerInterface as PsrContainerInterface;
Chris@14: use Symfony\Component\DependencyInjection\Exception\ServiceCircularReferenceException;
Chris@14: use Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException;
Chris@14: 
Chris@14: /**
Chris@14:  * @author Robin Chalas <robin.chalas@gmail.com>
Chris@14:  * @author Nicolas Grekas <p@tchwork.com>
Chris@14:  */
Chris@14: class ServiceLocator implements PsrContainerInterface
Chris@14: {
Chris@14:     private $factories;
Chris@17:     private $loading = [];
Chris@14:     private $externalId;
Chris@14:     private $container;
Chris@14: 
Chris@14:     /**
Chris@14:      * @param callable[] $factories
Chris@14:      */
Chris@14:     public function __construct(array $factories)
Chris@14:     {
Chris@14:         $this->factories = $factories;
Chris@14:     }
Chris@14: 
Chris@14:     /**
Chris@14:      * {@inheritdoc}
Chris@14:      */
Chris@14:     public function has($id)
Chris@14:     {
Chris@14:         return isset($this->factories[$id]);
Chris@14:     }
Chris@14: 
Chris@14:     /**
Chris@14:      * {@inheritdoc}
Chris@14:      */
Chris@14:     public function get($id)
Chris@14:     {
Chris@14:         if (!isset($this->factories[$id])) {
Chris@17:             throw new ServiceNotFoundException($id, end($this->loading) ?: null, null, [], $this->createServiceNotFoundMessage($id));
Chris@14:         }
Chris@14: 
Chris@14:         if (isset($this->loading[$id])) {
Chris@14:             $ids = array_values($this->loading);
Chris@17:             $ids = \array_slice($this->loading, array_search($id, $ids));
Chris@14:             $ids[] = $id;
Chris@14: 
Chris@14:             throw new ServiceCircularReferenceException($id, $ids);
Chris@14:         }
Chris@14: 
Chris@14:         $this->loading[$id] = $id;
Chris@14:         try {
Chris@14:             return $this->factories[$id]();
Chris@14:         } finally {
Chris@14:             unset($this->loading[$id]);
Chris@14:         }
Chris@14:     }
Chris@14: 
Chris@14:     public function __invoke($id)
Chris@14:     {
Chris@14:         return isset($this->factories[$id]) ? $this->get($id) : null;
Chris@14:     }
Chris@14: 
Chris@14:     /**
Chris@14:      * @internal
Chris@14:      */
Chris@14:     public function withContext($externalId, Container $container)
Chris@14:     {
Chris@14:         $locator = clone $this;
Chris@14:         $locator->externalId = $externalId;
Chris@14:         $locator->container = $container;
Chris@14: 
Chris@14:         return $locator;
Chris@14:     }
Chris@14: 
Chris@14:     private function createServiceNotFoundMessage($id)
Chris@14:     {
Chris@14:         if ($this->loading) {
Chris@14:             return sprintf('The service "%s" has a dependency on a non-existent service "%s". This locator %s', end($this->loading), $id, $this->formatAlternatives());
Chris@14:         }
Chris@14: 
Chris@14:         $class = debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT | DEBUG_BACKTRACE_IGNORE_ARGS, 3);
Chris@17:         $class = isset($class[2]['object']) ? \get_class($class[2]['object']) : null;
Chris@14:         $externalId = $this->externalId ?: $class;
Chris@14: 
Chris@17:         $msg = [];
Chris@17:         $msg[] = sprintf('Service "%s" not found:', $id);
Chris@14: 
Chris@14:         if (!$this->container) {
Chris@14:             $class = null;
Chris@14:         } elseif ($this->container->has($id) || isset($this->container->getRemovedIds()[$id])) {
Chris@17:             $msg[] = 'even though it exists in the app\'s container,';
Chris@14:         } else {
Chris@14:             try {
Chris@14:                 $this->container->get($id);
Chris@14:                 $class = null;
Chris@14:             } catch (ServiceNotFoundException $e) {
Chris@14:                 if ($e->getAlternatives()) {
Chris@17:                     $msg[] = sprintf('did you mean %s? Anyway,', $this->formatAlternatives($e->getAlternatives(), 'or'));
Chris@14:                 } else {
Chris@14:                     $class = null;
Chris@14:                 }
Chris@14:             }
Chris@14:         }
Chris@14:         if ($externalId) {
Chris@17:             $msg[] = sprintf('the container inside "%s" is a smaller service locator that %s', $externalId, $this->formatAlternatives());
Chris@14:         } else {
Chris@17:             $msg[] = sprintf('the current service locator %s', $this->formatAlternatives());
Chris@14:         }
Chris@14: 
Chris@14:         if (!$class) {
Chris@14:             // no-op
Chris@14:         } elseif (is_subclass_of($class, ServiceSubscriberInterface::class)) {
Chris@17:             $msg[] = sprintf('Unless you need extra laziness, try using dependency injection instead. Otherwise, you need to declare it using "%s::getSubscribedServices()".', preg_replace('/([^\\\\]++\\\\)++/', '', $class));
Chris@14:         } else {
Chris@17:             $msg[] = 'Try using dependency injection instead.';
Chris@14:         }
Chris@14: 
Chris@17:         return implode(' ', $msg);
Chris@14:     }
Chris@14: 
Chris@14:     private function formatAlternatives(array $alternatives = null, $separator = 'and')
Chris@14:     {
Chris@14:         $format = '"%s"%s';
Chris@14:         if (null === $alternatives) {
Chris@14:             if (!$alternatives = array_keys($this->factories)) {
Chris@14:                 return 'is empty...';
Chris@14:             }
Chris@17:             $format = sprintf('only knows about the %s service%s.', $format, 1 < \count($alternatives) ? 's' : '');
Chris@14:         }
Chris@14:         $last = array_pop($alternatives);
Chris@14: 
Chris@14:         return sprintf($format, $alternatives ? implode('", "', $alternatives) : $last, $alternatives ? sprintf(' %s "%s"', $separator, $last) : '');
Chris@14:     }
Chris@14: }