1<?php
2
3/**
4 * @file
5 * Contains \Drupal.
6 */
7
8use Drupal\Core\DependencyInjection\ContainerNotInitializedException;
9use Drupal\Core\Messenger\LegacyMessenger;
10use Drupal\Core\Url;
11use Symfony\Component\DependencyInjection\ContainerInterface;
12
13/**
14 * Static Service Container wrapper.
15 *
16 * Generally, code in Drupal should accept its dependencies via either
17 * constructor injection or setter method injection. However, there are cases,
18 * particularly in legacy procedural code, where that is infeasible. This
19 * class acts as a unified global accessor to arbitrary services within the
20 * system in order to ease the transition from procedural code to injected OO
21 * code.
22 *
23 * The container is built by the kernel and passed in to this class which stores
24 * it statically. The container always contains the services from
25 * \Drupal\Core\CoreServiceProvider, the service providers of enabled modules and any other
26 * service providers defined in $GLOBALS['conf']['container_service_providers'].
27 *
28 * This class exists only to support legacy code that cannot be dependency
29 * injected. If your code needs it, consider refactoring it to be object
30 * oriented, if possible. When this is not possible, for instance in the case of
31 * hook implementations, and your code is more than a few non-reusable lines, it
32 * is recommended to instantiate an object implementing the actual logic.
33 *
34 * @code
35 *   // Legacy procedural code.
36 *   function hook_do_stuff() {
37 *     $lock = lock()->acquire('stuff_lock');
38 *     // ...
39 *   }
40 *
41 *   // Correct procedural code.
42 *   function hook_do_stuff() {
43 *     $lock = \Drupal::lock()->acquire('stuff_lock');
44 *     // ...
45 *   }
46 *
47 *   // The preferred way: dependency injected code.
48 *   function hook_do_stuff() {
49 *     // Move the actual implementation to a class and instantiate it.
50 *     $instance = new StuffDoingClass(\Drupal::lock());
51 *     $instance->doStuff();
52 *
53 *     // Or, even better, rely on the service container to avoid hard coding a
54 *     // specific interface implementation, so that the actual logic can be
55 *     // swapped. This might not always make sense, but in general it is a good
56 *     // practice.
57 *     \Drupal::service('stuff.doing')->doStuff();
58 *   }
59 *
60 *   interface StuffDoingInterface {
61 *     public function doStuff();
62 *   }
63 *
64 *   class StuffDoingClass implements StuffDoingInterface {
65 *     protected $lockBackend;
66 *
67 *     public function __construct(LockBackendInterface $lock_backend) {
68 *       $this->lockBackend = $lock_backend;
69 *     }
70 *
71 *     public function doStuff() {
72 *       $lock = $this->lockBackend->acquire('stuff_lock');
73 *       // ...
74 *     }
75 *   }
76 * @endcode
77 *
78 * @see \Drupal\Core\DrupalKernel
79 */
80class Drupal {
81
82  /**
83   * The current system version.
84   */
85  const VERSION = '8.9.20';
86
87  /**
88   * Core API compatibility.
89   */
90  const CORE_COMPATIBILITY = '8.x';
91
92  /**
93   * Core minimum schema version.
94   */
95  const CORE_MINIMUM_SCHEMA_VERSION = 8000;
96
97  /**
98   * The currently active container object, or NULL if not initialized yet.
99   *
100   * @var \Symfony\Component\DependencyInjection\ContainerInterface|null
101   */
102  protected static $container;
103
104  /**
105   * Sets a new global container.
106   *
107   * @param \Symfony\Component\DependencyInjection\ContainerInterface $container
108   *   A new container instance to replace the current.
109   */
110  public static function setContainer(ContainerInterface $container) {
111    static::$container = $container;
112  }
113
114  /**
115   * Unsets the global container.
116   */
117  public static function unsetContainer() {
118    static::$container = NULL;
119  }
120
121  /**
122   * Returns the currently active global container.
123   *
124   * @return \Symfony\Component\DependencyInjection\ContainerInterface
125   *
126   * @throws \Drupal\Core\DependencyInjection\ContainerNotInitializedException
127   */
128  public static function getContainer() {
129    if (static::$container === NULL) {
130      throw new ContainerNotInitializedException('\Drupal::$container is not initialized yet. \Drupal::setContainer() must be called with a real container.');
131    }
132    return static::$container;
133  }
134
135  /**
136   * Returns TRUE if the container has been initialized, FALSE otherwise.
137   *
138   * @return bool
139   */
140  public static function hasContainer() {
141    return static::$container !== NULL;
142  }
143
144  /**
145   * Retrieves a service from the container.
146   *
147   * Use this method if the desired service is not one of those with a dedicated
148   * accessor method below. If it is listed below, those methods are preferred
149   * as they can return useful type hints.
150   *
151   * @param string $id
152   *   The ID of the service to retrieve.
153   *
154   * @return mixed
155   *   The specified service.
156   */
157  public static function service($id) {
158    return static::getContainer()->get($id);
159  }
160
161  /**
162   * Indicates if a service is defined in the container.
163   *
164   * @param string $id
165   *   The ID of the service to check.
166   *
167   * @return bool
168   *   TRUE if the specified service exists, FALSE otherwise.
169   */
170  public static function hasService($id) {
171    // Check hasContainer() first in order to always return a Boolean.
172    return static::hasContainer() && static::getContainer()->has($id);
173  }
174
175  /**
176   * Gets the app root.
177   *
178   * @return string
179   */
180  public static function root() {
181    return static::getContainer()->get('app.root');
182  }
183
184  /**
185   * Gets the active install profile.
186   *
187   * @return string|null
188   *   The name of the active install profile.
189   */
190  public static function installProfile() {
191    return static::getContainer()->getParameter('install_profile');
192  }
193
194  /**
195   * Indicates if there is a currently active request object.
196   *
197   * @return bool
198   *   TRUE if there is a currently active request object, FALSE otherwise.
199   */
200  public static function hasRequest() {
201    // Check hasContainer() first in order to always return a Boolean.
202    return static::hasContainer() && static::getContainer()->has('request_stack') && static::getContainer()->get('request_stack')->getCurrentRequest() !== NULL;
203  }
204
205  /**
206   * Retrieves the currently active request object.
207   *
208   * Note: The use of this wrapper in particular is especially discouraged. Most
209   * code should not need to access the request directly.  Doing so means it
210   * will only function when handling an HTTP request, and will require special
211   * modification or wrapping when run from a command line tool, from certain
212   * queue processors, or from automated tests.
213   *
214   * If code must access the request, it is considerably better to register
215   * an object with the Service Container and give it a setRequest() method
216   * that is configured to run when the service is created.  That way, the
217   * correct request object can always be provided by the container and the
218   * service can still be unit tested.
219   *
220   * If this method must be used, never save the request object that is
221   * returned.  Doing so may lead to inconsistencies as the request object is
222   * volatile and may change at various times, such as during a subrequest.
223   *
224   * @return \Symfony\Component\HttpFoundation\Request
225   *   The currently active request object.
226   */
227  public static function request() {
228    return static::getContainer()->get('request_stack')->getCurrentRequest();
229  }
230
231  /**
232   * Retrieves the request stack.
233   *
234   * @return \Symfony\Component\HttpFoundation\RequestStack
235   *   The request stack
236   */
237  public static function requestStack() {
238    return static::getContainer()->get('request_stack');
239  }
240
241  /**
242   * Retrieves the currently active route match object.
243   *
244   * @return \Drupal\Core\Routing\RouteMatchInterface
245   *   The currently active route match object.
246   */
247  public static function routeMatch() {
248    return static::getContainer()->get('current_route_match');
249  }
250
251  /**
252   * Gets the current active user.
253   *
254   * This method will return the \Drupal\Core\Session\AccountProxy object of the
255   * current user. You can use the \Drupal\user\Entity\User::load() method to
256   * load the full user entity object. For example:
257   * @code
258   *   $user = \Drupal\user\Entity\User::load(\Drupal::currentUser()->id());
259   * @endcode
260   *
261   * @return \Drupal\Core\Session\AccountProxyInterface
262   */
263  public static function currentUser() {
264    return static::getContainer()->get('current_user');
265  }
266
267  /**
268   * Retrieves the entity manager service.
269   *
270   * @return \Drupal\Core\Entity\EntityManagerInterface
271   *   The entity manager service.
272   *
273   * @deprecated in drupal:8.0.0 and is removed from drupal:9.0.0.
274   *   Use \Drupal::entityTypeManager() instead in most cases. If the needed
275   *   method is not on \Drupal\Core\Entity\EntityTypeManagerInterface, see the
276   *   deprecated \Drupal\Core\Entity\EntityManager to find the
277   *   correct interface or service.
278   */
279  public static function entityManager() {
280    @trigger_error("\Drupal::entityManager() is deprecated in Drupal 8.0.0 and will be removed before Drupal 9.0.0. Use \Drupal::entityTypeManager() instead in most cases. If the needed method is not on \Drupal\Core\Entity\EntityTypeManagerInterface, see the deprecated \Drupal\Core\Entity\EntityManager to find the correct interface or service. See https://www.drupal.org/node/2549139", E_USER_DEPRECATED);
281    return static::getContainer()->get('entity.manager');
282  }
283
284  /**
285   * Retrieves the entity type manager.
286   *
287   * @return \Drupal\Core\Entity\EntityTypeManagerInterface
288   *   The entity type manager.
289   */
290  public static function entityTypeManager() {
291    return static::getContainer()->get('entity_type.manager');
292  }
293
294  /**
295   * Returns the current primary database.
296   *
297   * @return \Drupal\Core\Database\Connection
298   *   The current active database's master connection.
299   */
300  public static function database() {
301    return static::getContainer()->get('database');
302  }
303
304  /**
305   * Returns the requested cache bin.
306   *
307   * @param string $bin
308   *   (optional) The cache bin for which the cache object should be returned,
309   *   defaults to 'default'.
310   *
311   * @return \Drupal\Core\Cache\CacheBackendInterface
312   *   The cache object associated with the specified bin.
313   *
314   * @ingroup cache
315   */
316  public static function cache($bin = 'default') {
317    return static::getContainer()->get('cache.' . $bin);
318  }
319
320  /**
321   * Retrieves the class resolver.
322   *
323   * This is to be used in procedural code such as module files to instantiate
324   * an object of a class that implements
325   * \Drupal\Core\DependencyInjection\ContainerInjectionInterface.
326   *
327   * One common usecase is to provide a class which contains the actual code
328   * of a hook implementation, without having to create a service.
329   *
330   * @param string $class
331   *   (optional) A class name to instantiate.
332   *
333   * @return \Drupal\Core\DependencyInjection\ClassResolverInterface|object
334   *   The class resolver or if $class is provided, a class instance with a
335   *   given class definition.
336   *
337   * @throws \InvalidArgumentException
338   *   If $class does not exist.
339   */
340  public static function classResolver($class = NULL) {
341    if ($class) {
342      return static::getContainer()->get('class_resolver')->getInstanceFromDefinition($class);
343    }
344    return static::getContainer()->get('class_resolver');
345  }
346
347  /**
348   * Returns an expirable key value store collection.
349   *
350   * @param string $collection
351   *   The name of the collection holding key and value pairs.
352   *
353   * @return \Drupal\Core\KeyValueStore\KeyValueStoreExpirableInterface
354   *   An expirable key value store collection.
355   */
356  public static function keyValueExpirable($collection) {
357    return static::getContainer()->get('keyvalue.expirable')->get($collection);
358  }
359
360  /**
361   * Returns the locking layer instance.
362   *
363   * @return \Drupal\Core\Lock\LockBackendInterface
364   *
365   * @ingroup lock
366   */
367  public static function lock() {
368    return static::getContainer()->get('lock');
369  }
370
371  /**
372   * Retrieves a configuration object.
373   *
374   * This is the main entry point to the configuration API. Calling
375   * @code \Drupal::config('book.admin') @endcode will return a configuration
376   * object the Book module can use to read its administrative settings.
377   *
378   * @param string $name
379   *   The name of the configuration object to retrieve, which typically
380   *   corresponds to a configuration file. For
381   *   @code \Drupal::config('book.admin') @endcode, the configuration
382   *   object returned will contain the content of the book.admin
383   *   configuration file.
384   *
385   * @return \Drupal\Core\Config\ImmutableConfig
386   *   An immutable configuration object.
387   */
388  public static function config($name) {
389    return static::getContainer()->get('config.factory')->get($name);
390  }
391
392  /**
393   * Retrieves the configuration factory.
394   *
395   * This is mostly used to change the override settings on the configuration
396   * factory. For example, changing the language, or turning all overrides on
397   * or off.
398   *
399   * @return \Drupal\Core\Config\ConfigFactoryInterface
400   *   The configuration factory service.
401   */
402  public static function configFactory() {
403    return static::getContainer()->get('config.factory');
404  }
405
406  /**
407   * Returns a queue for the given queue name.
408   *
409   * The following values can be set in your settings.php file's $settings
410   * array to define which services are used for queues:
411   * - queue_reliable_service_$name: The container service to use for the
412   *   reliable queue $name.
413   * - queue_service_$name: The container service to use for the
414   *   queue $name.
415   * - queue_default: The container service to use by default for queues
416   *   without overrides. This defaults to 'queue.database'.
417   *
418   * @param string $name
419   *   The name of the queue to work with.
420   * @param bool $reliable
421   *   (optional) TRUE if the ordering of items and guaranteeing every item
422   *   executes at least once is important, FALSE if scalability is the main
423   *   concern. Defaults to FALSE.
424   *
425   * @return \Drupal\Core\Queue\QueueInterface
426   *   The queue object for a given name.
427   */
428  public static function queue($name, $reliable = FALSE) {
429    return static::getContainer()->get('queue')->get($name, $reliable);
430  }
431
432  /**
433   * Returns a key/value storage collection.
434   *
435   * @param string $collection
436   *   Name of the key/value collection to return.
437   *
438   * @return \Drupal\Core\KeyValueStore\KeyValueStoreInterface
439   */
440  public static function keyValue($collection) {
441    return static::getContainer()->get('keyvalue')->get($collection);
442  }
443
444  /**
445   * Returns the state storage service.
446   *
447   * Use this to store machine-generated data, local to a specific environment
448   * that does not need deploying and does not need human editing; for example,
449   * the last time cron was run. Data which needs to be edited by humans and
450   * needs to be the same across development, production, etc. environments
451   * (for example, the system maintenance message) should use \Drupal::config() instead.
452   *
453   * @return \Drupal\Core\State\StateInterface
454   */
455  public static function state() {
456    return static::getContainer()->get('state');
457  }
458
459  /**
460   * Returns the default http client.
461   *
462   * @return \GuzzleHttp\Client
463   *   A guzzle http client instance.
464   */
465  public static function httpClient() {
466    return static::getContainer()->get('http_client');
467  }
468
469  /**
470   * Returns the entity query object for this entity type.
471   *
472   * @param string $entity_type
473   *   The entity type (for example, node) for which the query object should be
474   *   returned.
475   * @param string $conjunction
476   *   (optional) Either 'AND' if all conditions in the query need to apply, or
477   *   'OR' if any of them is sufficient. Defaults to 'AND'.
478   *
479   * @return \Drupal\Core\Entity\Query\QueryInterface
480   *   The query object that can query the given entity type.
481   */
482  public static function entityQuery($entity_type, $conjunction = 'AND') {
483    return static::entityTypeManager()->getStorage($entity_type)->getQuery($conjunction);
484  }
485
486  /**
487   * Returns the entity query aggregate object for this entity type.
488   *
489   * @param string $entity_type
490   *   The entity type (for example, node) for which the query object should be
491   *   returned.
492   * @param string $conjunction
493   *   (optional) Either 'AND' if all conditions in the query need to apply, or
494   *   'OR' if any of them is sufficient. Defaults to 'AND'.
495   *
496   * @return \Drupal\Core\Entity\Query\QueryAggregateInterface
497   *   The query object that can query the given entity type.
498   */
499  public static function entityQueryAggregate($entity_type, $conjunction = 'AND') {
500    return static::entityTypeManager()->getStorage($entity_type)->getAggregateQuery($conjunction);
501  }
502
503  /**
504   * Returns the flood instance.
505   *
506   * @return \Drupal\Core\Flood\FloodInterface
507   */
508  public static function flood() {
509    return static::getContainer()->get('flood');
510  }
511
512  /**
513   * Returns the module handler.
514   *
515   * @return \Drupal\Core\Extension\ModuleHandlerInterface
516   */
517  public static function moduleHandler() {
518    return static::getContainer()->get('module_handler');
519  }
520
521  /**
522   * Returns the typed data manager service.
523   *
524   * Use the typed data manager service for creating typed data objects.
525   *
526   * @return \Drupal\Core\TypedData\TypedDataManagerInterface
527   *   The typed data manager.
528   *
529   * @see \Drupal\Core\TypedData\TypedDataManager::create()
530   */
531  public static function typedDataManager() {
532    return static::getContainer()->get('typed_data_manager');
533  }
534
535  /**
536   * Returns the token service.
537   *
538   * @return \Drupal\Core\Utility\Token
539   *   The token service.
540   */
541  public static function token() {
542    return static::getContainer()->get('token');
543  }
544
545  /**
546   * Returns the url generator service.
547   *
548   * @return \Drupal\Core\Routing\UrlGeneratorInterface
549   *   The url generator service.
550   */
551  public static function urlGenerator() {
552    return static::getContainer()->get('url_generator');
553  }
554
555  /**
556   * Generates a URL string for a specific route based on the given parameters.
557   *
558   * This method is a convenience wrapper for generating URL strings for URLs
559   * that have Drupal routes (that is, most pages generated by Drupal) using
560   * the \Drupal\Core\Url object. See \Drupal\Core\Url::fromRoute() for
561   * detailed documentation. For non-routed local URIs relative to
562   * the base path (like robots.txt) use Url::fromUri()->toString() with the
563   * base: scheme.
564   *
565   * @param string $route_name
566   *   The name of the route.
567   * @param array $route_parameters
568   *   (optional) An associative array of parameter names and values.
569   * @param array $options
570   *   (optional) An associative array of additional options.
571   * @param bool $collect_bubbleable_metadata
572   *   (optional) Defaults to FALSE. When TRUE, both the generated URL and its
573   *   associated bubbleable metadata are returned.
574   *
575   * @return string|\Drupal\Core\GeneratedUrl
576   *   A string containing a URL to the given path.
577   *   When $collect_bubbleable_metadata is TRUE, a GeneratedUrl object is
578   *   returned, containing the generated URL plus bubbleable metadata.
579   *
580   * @see \Drupal\Core\Routing\UrlGeneratorInterface::generateFromRoute()
581   * @see \Drupal\Core\Url
582   * @see \Drupal\Core\Url::fromRoute()
583   * @see \Drupal\Core\Url::fromUri()
584   *
585   * @deprecated in drupal:8.0.0 and is removed from drupal:9.0.0.
586   *   Instead create a \Drupal\Core\Url object directly, for example using
587   *   Url::fromRoute().
588   */
589  public static function url($route_name, $route_parameters = [], $options = [], $collect_bubbleable_metadata = FALSE) {
590    @trigger_error('Drupal::url() is deprecated as of Drupal 8.0.x, will be removed before Drupal 9.0.0. Instead create a \Drupal\Core\Url object directly, for example using Url::fromRoute()', E_USER_DEPRECATED);
591    return static::getContainer()->get('url_generator')->generateFromRoute($route_name, $route_parameters, $options, $collect_bubbleable_metadata);
592  }
593
594  /**
595   * Returns the link generator service.
596   *
597   * @return \Drupal\Core\Utility\LinkGeneratorInterface
598   */
599  public static function linkGenerator() {
600    return static::getContainer()->get('link_generator');
601  }
602
603  /**
604   * Renders a link with a given link text and Url object.
605   *
606   * This method is a convenience wrapper for the link generator service's
607   * generate() method.
608   *
609   * @param string|array|\Drupal\Component\Render\MarkupInterface $text
610   *   The link text for the anchor tag as a translated string or render array.
611   * @param \Drupal\Core\Url $url
612   *   The URL object used for the link.
613   *
614   * @return \Drupal\Core\GeneratedLink
615   *   A GeneratedLink object containing a link to the given route and
616   *   parameters and bubbleable metadata.
617   *
618   * @deprecated in drupal:8.0.0 and is removed from drupal:9.0.0. Use
619   * \Drupal\Core\Link::fromTextAndUrl() instead.
620   *
621   * @see https://www.drupal.org/node/2614344
622   * @see \Drupal\Core\Utility\LinkGeneratorInterface::generate()
623   * @see \Drupal\Core\Url
624   */
625  public static function l($text, Url $url) {
626    @trigger_error('\Drupal::l() is deprecated in drupal:8.0.0 and is removed from drupal:9.0.0. Use \Drupal\Core\Link::fromTextAndUrl() instead. See https://www.drupal.org/node/2614344', E_USER_DEPRECATED);
627    return static::getContainer()->get('link_generator')->generate($text, $url);
628  }
629
630  /**
631   * Returns the string translation service.
632   *
633   * @return \Drupal\Core\StringTranslation\TranslationManager
634   *   The string translation manager.
635   */
636  public static function translation() {
637    return static::getContainer()->get('string_translation');
638  }
639
640  /**
641   * Returns the language manager service.
642   *
643   * @return \Drupal\Core\Language\LanguageManagerInterface
644   *   The language manager.
645   */
646  public static function languageManager() {
647    return static::getContainer()->get('language_manager');
648  }
649
650  /**
651   * Returns the CSRF token manager service.
652   *
653   * The generated token is based on the session ID of the current user. Normally,
654   * anonymous users do not have a session, so the generated token will be
655   * different on every page request. To generate a token for users without a
656   * session, manually start a session prior to calling this function.
657   *
658   * @return \Drupal\Core\Access\CsrfTokenGenerator
659   *   The CSRF token manager.
660   *
661   * @see \Drupal\Core\Session\SessionManager::start()
662   */
663  public static function csrfToken() {
664    return static::getContainer()->get('csrf_token');
665  }
666
667  /**
668   * Returns the transliteration service.
669   *
670   * @return \Drupal\Core\Transliteration\PhpTransliteration
671   *   The transliteration manager.
672   */
673  public static function transliteration() {
674    return static::getContainer()->get('transliteration');
675  }
676
677  /**
678   * Returns the form builder service.
679   *
680   * @return \Drupal\Core\Form\FormBuilderInterface
681   *   The form builder.
682   */
683  public static function formBuilder() {
684    return static::getContainer()->get('form_builder');
685  }
686
687  /**
688   * Gets the theme service.
689   *
690   * @return \Drupal\Core\Theme\ThemeManagerInterface
691   */
692  public static function theme() {
693    return static::getContainer()->get('theme.manager');
694  }
695
696  /**
697   * Gets the syncing state.
698   *
699   * @return bool
700   *   Returns TRUE is syncing flag set.
701   */
702  public static function isConfigSyncing() {
703    return static::getContainer()->get('config.installer')->isSyncing();
704  }
705
706  /**
707   * Returns a channel logger object.
708   *
709   * @param string $channel
710   *   The name of the channel. Can be any string, but the general practice is
711   *   to use the name of the subsystem calling this.
712   *
713   * @return \Psr\Log\LoggerInterface
714   *   The logger for this channel.
715   */
716  public static function logger($channel) {
717    return static::getContainer()->get('logger.factory')->get($channel);
718  }
719
720  /**
721   * Returns the menu tree.
722   *
723   * @return \Drupal\Core\Menu\MenuLinkTreeInterface
724   *   The menu tree.
725   */
726  public static function menuTree() {
727    return static::getContainer()->get('menu.link_tree');
728  }
729
730  /**
731   * Returns the path validator.
732   *
733   * @return \Drupal\Core\Path\PathValidatorInterface
734   */
735  public static function pathValidator() {
736    return static::getContainer()->get('path.validator');
737  }
738
739  /**
740   * Returns the access manager service.
741   *
742   * @return \Drupal\Core\Access\AccessManagerInterface
743   *   The access manager service.
744   */
745  public static function accessManager() {
746    return static::getContainer()->get('access_manager');
747  }
748
749  /**
750   * Returns the redirect destination helper.
751   *
752   * @return \Drupal\Core\Routing\RedirectDestinationInterface
753   *   The redirect destination helper.
754   */
755  public static function destination() {
756    return static::getContainer()->get('redirect.destination');
757  }
758
759  /**
760   * Returns the entity definition update manager.
761   *
762   * @return \Drupal\Core\Entity\EntityDefinitionUpdateManagerInterface
763   *   The entity definition update manager.
764   */
765  public static function entityDefinitionUpdateManager() {
766    return static::getContainer()->get('entity.definition_update_manager');
767  }
768
769  /**
770   * Returns the time service.
771   *
772   * @return \Drupal\Component\Datetime\TimeInterface
773   *   The time service.
774   */
775  public static function time() {
776    return static::getContainer()->get('datetime.time');
777  }
778
779  /**
780   * Returns the messenger.
781   *
782   * @return \Drupal\Core\Messenger\MessengerInterface
783   *   The messenger.
784   */
785  public static function messenger() {
786    // @todo Replace with service once LegacyMessenger is removed in 9.0.0.
787    // @see https://www.drupal.org/node/2928994
788    return new LegacyMessenger();
789  }
790
791}
792