class Container in Drupal 9

Provides a container optimized for Drupal's needs.

This container implementation is compatible with the default Symfony dependency injection container and similar to the Symfony ContainerBuilder class, but optimized for speed.

It is based on a PHP array container definition dumped as a performance-optimized machine-readable format.

The best way to initialize this container is to use a Container Builder, compile it and then retrieve the definition via \Drupal\Component\DependencyInjection\Dumper\OptimizedPhpArrayDumper::getArray().

The retrieved array can be cached safely and then passed to this container via the constructor.

As the container is unfrozen by default, a second parameter can be passed to the container to "freeze" the parameter bag.

This container is different in behavior from the default Symfony container in the following ways:

• It only allows lowercase service and parameter names, though it does only enforce it via assertions for performance reasons.
• The following functions, that are not part of the interface, are explicitly not supported: getParameterBag(), isFrozen(), compile(), getAServiceWithAnIdByCamelCase().
• The function getServiceIds() was added as it has a use-case in core and contrib.

Hierarchy

• class \Drupal\Component\DependencyInjection\Container implements \Symfony\Component\DependencyInjection\ContainerInterface, \Symfony\Contracts\Service\ResetInterface

Related topics

Services and Dependency Injection Container

Overview of the Dependency Injection Container and Services.

1 file declares its use of Container

Container.php in core/lib/Drupal/Core/DependencyInjection/Container.php

3 string references to 'Container'

ClaroVerticalTabsTest::testVerticalTabs in core/tests/Drupal/KernelTests/Core/Theme/ClaroVerticalTabsTest.php

Confirms that Claro can render vertical tabs correctly.

field.field.taxonomy_term.forums.forum_container.yml in core/modules/forum/config/optional/field.field.taxonomy_term.forums.forum_container.yml

core/modules/forum/config/optional/field.field.taxonomy_term.forums.forum_container.yml

SearchExcerptTest::testSearchExcerptSimplified in core/modules/search/tests/src/Kernel/SearchExcerptTest.php

Tests search_excerpt() with search keywords matching simplified words.

File

core/lib/Drupal/Component/DependencyInjection/Container.php, line 47

Namespace

Drupal\Component\DependencyInjection

class Container implements ContainerInterface, ResetInterface {

  /**
   * The parameters of the container.
   *
   * @var array
   */
  protected $parameters = [];

  /**
   * The aliases of the container.
   *
   * @var array
   */
  protected $aliases = [];

  /**
   * The service definitions of the container.
   *
   * @var array
   */
  protected $serviceDefinitions = [];

  /**
   * The instantiated services.
   *
   * @var array
   */
  protected $services = [];

  /**
   * The instantiated private services.
   *
   * @var array
   */
  protected $privateServices = [];

  /**
   * The currently loading services.
   *
   * @var array
   */
  protected $loading = [];

  /**
   * Whether the container parameters can still be changed.
   *
   * For testing purposes the container needs to be changed.
   *
   * @var bool
   */
  protected $frozen = TRUE;

  /**
   * Constructs a new Container instance.
   *
   * @param array $container_definition
   *   An array containing the following keys:
   *   - aliases: The aliases of the container.
   *   - parameters: The parameters of the container.
   *   - services: The service definitions of the container.
   *   - frozen: Whether the container definition came from a frozen
   *     container builder or not.
   *   - machine_format: Whether this container definition uses the optimized
   *     machine-readable container format.
   */
  public function __construct(array $container_definition = []) {
    if (!empty($container_definition) && (!isset($container_definition['machine_format']) || $container_definition['machine_format'] !== TRUE)) {
      throw new InvalidArgumentException('The non-optimized format is not supported by this class. Use an optimized machine-readable format instead, e.g. as produced by \\Drupal\\Component\\DependencyInjection\\Dumper\\OptimizedPhpArrayDumper.');
    }
    $this->aliases = isset($container_definition['aliases']) ? $container_definition['aliases'] : [];
    $this->parameters = isset($container_definition['parameters']) ? $container_definition['parameters'] : [];
    $this->serviceDefinitions = isset($container_definition['services']) ? $container_definition['services'] : [];
    $this->frozen = isset($container_definition['frozen']) ? $container_definition['frozen'] : FALSE;

    // Register the service_container with itself.
    $this->services['service_container'] = $this;
  }

  /**
   * {@inheritdoc}
   */
  public function get($id, $invalid_behavior = ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE) {
    if ($this
      ->hasParameter('_deprecated_service_list')) {
      if ($deprecation = $this
        ->getParameter('_deprecated_service_list')[$id] ?? '') {
        @trigger_error($deprecation, E_USER_DEPRECATED);
      }
    }
    if (isset($this->aliases[$id])) {
      $id = $this->aliases[$id];
    }

    // Re-use shared service instance if it exists.
    if (isset($this->services[$id]) || $invalid_behavior === ContainerInterface::NULL_ON_INVALID_REFERENCE && array_key_exists($id, $this->services)) {
      return $this->services[$id];
    }
    if (isset($this->loading[$id])) {
      throw new ServiceCircularReferenceException($id, array_keys($this->loading));
    }
    $definition = isset($this->serviceDefinitions[$id]) ? $this->serviceDefinitions[$id] : NULL;
    if (!$definition && $invalid_behavior === ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE) {
      if (!$id) {
        throw new ServiceNotFoundException('');
      }
      throw new ServiceNotFoundException($id, NULL, NULL, $this
        ->getServiceAlternatives($id));
    }

    // In case something else than ContainerInterface::NULL_ON_INVALID_REFERENCE
    // is used, the actual wanted behavior is to re-try getting the service at a
    // later point.
    if (!$definition) {
      return;
    }

    // Definition is a keyed array, so [0] is only defined when it is a
    // serialized string.
    if (isset($definition[0])) {
      $definition = unserialize($definition);
    }

    // Now create the service.
    $this->loading[$id] = TRUE;
    try {
      $service = $this
        ->createService($definition, $id);
    } catch (\Exception $e) {
      unset($this->loading[$id]);
      unset($this->services[$id]);
      if (ContainerInterface::EXCEPTION_ON_INVALID_REFERENCE !== $invalid_behavior) {
        return;
      }
      throw $e;
    }
    unset($this->loading[$id]);
    return $service;
  }

  /**
   * Resets shared services from the container.
   *
   * The container is not intended to be used again after being reset in a
   * normal workflow. This method is meant as a way to release references for
   * ref-counting. A subsequent call to ContainerInterface::get() will recreate
   * a new instance of the shared service.
   */
  public function reset() {
    if (!empty($this->scopedServices)) {
      throw new LogicException('Resetting the container is not allowed when a scope is active.');
    }
    $this->services = [];
  }

  /**
   * Creates a service from a service definition.
   *
   * @param array $definition
   *   The service definition to create a service from.
   * @param string $id
   *   The service identifier, necessary so it can be shared if its public.
   *
   * @return object
   *   The service described by the service definition.
   *
   * @throws \Symfony\Component\DependencyInjection\Exception\RuntimeException
   *   Thrown when the service is a synthetic service.
   * @throws \Symfony\Component\DependencyInjection\Exception\InvalidArgumentException
   *   Thrown when the configurator callable in $definition['configurator'] is
   *   not actually a callable.
   * @throws \ReflectionException
   *   Thrown when the service class takes more than 10 parameters to construct,
   *   and cannot be instantiated.
   */
  protected function createService(array $definition, $id) {
    if (isset($definition['synthetic']) && $definition['synthetic'] === TRUE) {
      throw new RuntimeException(sprintf('You have requested a synthetic service ("%s"). The service container does not know how to construct this service. The service will need to be set before it is first used.', $id));
    }
    $arguments = [];
    if (isset($definition['arguments'])) {
      $arguments = $definition['arguments'];
      if ($arguments instanceof \stdClass) {
        $arguments = $this
          ->resolveServicesAndParameters($arguments);
      }
    }
    if (isset($definition['file'])) {
      $file = $this->frozen ? $definition['file'] : current($this
        ->resolveServicesAndParameters([
        $definition['file'],
      ]));
      require_once $file;
    }
    if (isset($definition['factory'])) {
      $factory = $definition['factory'];
      if (is_array($factory)) {
        $factory = $this
          ->resolveServicesAndParameters([
          $factory[0],
          $factory[1],
        ]);
      }
      elseif (!is_string($factory)) {
        throw new RuntimeException(sprintf('Cannot create service "%s" because of invalid factory', $id));
      }
      $service = call_user_func_array($factory, $arguments);
    }
    else {
      $class = $this->frozen ? $definition['class'] : current($this
        ->resolveServicesAndParameters([
        $definition['class'],
      ]));
      $service = new $class(...$arguments);
    }
    if (!isset($definition['shared']) || $definition['shared'] !== FALSE) {
      $this->services[$id] = $service;
    }
    if (isset($definition['calls'])) {
      foreach ($definition['calls'] as $call) {
        $method = $call[0];
        $arguments = [];
        if (!empty($call[1])) {
          $arguments = $call[1];
          if ($arguments instanceof \stdClass) {
            $arguments = $this
              ->resolveServicesAndParameters($arguments);
          }
        }
        call_user_func_array([
          $service,
          $method,
        ], $arguments);
      }
    }
    if (isset($definition['properties'])) {
      if ($definition['properties'] instanceof \stdClass) {
        $definition['properties'] = $this
          ->resolveServicesAndParameters($definition['properties']);
      }
      foreach ($definition['properties'] as $key => $value) {
        $service->{$key} = $value;
      }
    }
    if (isset($definition['configurator'])) {
      $callable = $definition['configurator'];
      if (is_array($callable)) {
        $callable = $this
          ->resolveServicesAndParameters($callable);
      }
      if (!is_callable($callable)) {
        throw new InvalidArgumentException(sprintf('The configurator for class "%s" is not a callable.', get_class($service)));
      }
      call_user_func($callable, $service);
    }
    return $service;
  }

  /**
   * {@inheritdoc}
   */
  public function set($id, $service) {
    $this->services[$id] = $service;
  }

  /**
   * {@inheritdoc}
   */
  public function has($id) {
    return isset($this->aliases[$id]) || isset($this->services[$id]) || isset($this->serviceDefinitions[$id]);
  }

  /**
   * {@inheritdoc}
   */
  public function getParameter($name) {
    if (!(isset($this->parameters[$name]) || array_key_exists($name, $this->parameters))) {
      if (!$name) {
        throw new ParameterNotFoundException('');
      }
      throw new ParameterNotFoundException($name, NULL, NULL, NULL, $this
        ->getParameterAlternatives($name));
    }
    return $this->parameters[$name];
  }

  /**
   * {@inheritdoc}
   */
  public function hasParameter($name) {
    return isset($this->parameters[$name]) || array_key_exists($name, $this->parameters);
  }

  /**
   * {@inheritdoc}
   */
  public function setParameter($name, $value) {
    if ($this->frozen) {
      throw new LogicException('Impossible to call set() on a frozen ParameterBag.');
    }
    $this->parameters[$name] = $value;
  }

  /**
   * {@inheritdoc}
   */
  public function initialized($id) {
    if (isset($this->aliases[$id])) {
      $id = $this->aliases[$id];
    }
    return isset($this->services[$id]) || array_key_exists($id, $this->services);
  }

  /**
   * Resolves arguments that represent services or variables to the real values.
   *
   * @param array|object $arguments
   *   The arguments to resolve.
   *
   * @return array
   *   The resolved arguments.
   *
   * @throws \Symfony\Component\DependencyInjection\Exception\RuntimeException
   *   If a parameter/service could not be resolved.
   * @throws \Symfony\Component\DependencyInjection\Exception\InvalidArgumentException
   *   If an unknown type is met while resolving parameters and services.
   */
  protected function resolveServicesAndParameters($arguments) {

    // Check if this collection needs to be resolved.
    if ($arguments instanceof \stdClass) {
      if ($arguments->type !== 'collection') {
        throw new InvalidArgumentException(sprintf('Undefined type "%s" while resolving parameters and services.', $arguments->type));
      }

      // In case there is nothing to resolve, we are done here.
      if (!$arguments->resolve) {
        return $arguments->value;
      }
      $arguments = $arguments->value;
    }

    // Process the arguments.
    foreach ($arguments as $key => $argument) {

      // For this machine-optimized format, only \stdClass arguments are
      // processed and resolved. All other values are kept as is.
      if ($argument instanceof \stdClass) {
        $type = $argument->type;

        // Check for parameter.
        if ($type == 'parameter') {
          $name = $argument->name;
          if (!isset($this->parameters[$name])) {
            $arguments[$key] = $this
              ->getParameter($name);

            // This can never be reached as getParameter() throws an Exception,
            // because we already checked that the parameter is not set above.
          }

          // Update argument.
          $argument = $arguments[$key] = $this->parameters[$name];

          // In case there is not a machine readable value (e.g. a service)
          // behind this resolved parameter, continue.
          if (!$argument instanceof \stdClass) {
            continue;
          }

          // Fall through.
          $type = $argument->type;
        }

        // Create a service.
        if ($type == 'service') {
          $id = $argument->id;

          // Does the service already exist?
          if (isset($this->aliases[$id])) {
            $id = $this->aliases[$id];
          }
          if (isset($this->services[$id])) {
            $arguments[$key] = $this->services[$id];
            continue;
          }

          // Return the service.
          $arguments[$key] = $this
            ->get($id, $argument->invalidBehavior);
          continue;
        }
        elseif ($type == 'private_service') {
          $id = $argument->id;

          // Does the private service already exist.
          if (isset($this->privateServices[$id])) {
            $arguments[$key] = $this->privateServices[$id];
            continue;
          }

          // Create the private service.
          $arguments[$key] = $this
            ->createService($argument->value, $id);
          if ($argument->shared) {
            $this->privateServices[$id] = $arguments[$key];
          }
          continue;
        }
        elseif ($type == 'collection') {
          $value = $argument->value;

          // Does this collection need resolving?
          if ($argument->resolve) {
            $arguments[$key] = $this
              ->resolveServicesAndParameters($value);
          }
          else {
            $arguments[$key] = $value;
          }
          continue;
        }
        elseif ($type == 'raw') {
          $arguments[$key] = $argument->value;
          continue;
        }
        if ($type !== NULL) {
          throw new InvalidArgumentException(sprintf('Undefined type "%s" while resolving parameters and services.', $type));
        }
      }
    }
    return $arguments;
  }

  /**
   * Provides alternatives for a given array and key.
   *
   * @param string $search_key
   *   The search key to get alternatives for.
   * @param array $keys
   *   The search space to search for alternatives in.
   *
   * @return string[]
   *   An array of strings with suitable alternatives.
   */
  protected function getAlternatives($search_key, array $keys) {
    $alternatives = [];
    foreach ($keys as $key) {
      $lev = levenshtein($search_key, $key);
      if ($lev <= strlen($search_key) / 3 || strpos($key, $search_key) !== FALSE) {
        $alternatives[] = $key;
      }
    }
    return $alternatives;
  }

  /**
   * Provides alternatives in case a service was not found.
   *
   * @param string $id
   *   The service to get alternatives for.
   *
   * @return string[]
   *   An array of strings with suitable alternatives.
   */
  protected function getServiceAlternatives($id) {
    $all_service_keys = array_unique(array_merge(array_keys($this->services), array_keys($this->serviceDefinitions)));
    return $this
      ->getAlternatives($id, $all_service_keys);
  }

  /**
   * Provides alternatives in case a parameter was not found.
   *
   * @param string $name
   *   The parameter to get alternatives for.
   *
   * @return string[]
   *   An array of strings with suitable alternatives.
   */
  protected function getParameterAlternatives($name) {
    return $this
      ->getAlternatives($name, array_keys($this->parameters));
  }

  /**
   * Gets all defined service IDs.
   *
   * @return array
   *   An array of all defined service IDs.
   */
  public function getServiceIds() {
    return array_keys($this->serviceDefinitions + $this->services);
  }

  /**
   * Ensure that cloning doesn't work.
   */
  private function __clone() {
  }

}

Members

Name	Modifiers	Type	Description	Overrides
Container::$aliases	protected	property	The aliases of the container.
Container::$frozen	protected	property	Whether the container parameters can still be changed.
Container::$loading	protected	property	The currently loading services.
Container::$parameters	protected	property	The parameters of the container.
Container::$privateServices	protected	property	The instantiated private services.
Container::$serviceDefinitions	protected	property	The service definitions of the container.
Container::$services	protected	property	The instantiated services.
Container::createService	protected	function	Creates a service from a service definition.	1
Container::get	public	function		2
Container::getAlternatives	protected	function	Provides alternatives for a given array and key.
Container::getParameter	public	function
Container::getParameterAlternatives	protected	function	Provides alternatives in case a parameter was not found.
Container::getServiceAlternatives	protected	function	Provides alternatives in case a service was not found.
Container::getServiceIds	public	function	Gets all defined service IDs.
Container::has	public	function
Container::hasParameter	public	function
Container::initialized	public	function
Container::reset	public	function	Resets shared services from the container.
Container::resolveServicesAndParameters	protected	function	Resolves arguments that represent services or variables to the real values.	1
Container::set	public	function		1
Container::setParameter	public	function
Container::__clone	private	function	Ensure that cloning doesn't work.
Container::__construct	public	function	Constructs a new Container instance.	1