Error message
Deprecated function: unserialize(): Passing null to parameter #1 ($data) of type string is deprecated in Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (line 474 of core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php).
Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (Line: 428) Drupal\Core\Entity\Sql\SqlContentEntityStorage->getFromStorage() (Line: 394) Drupal\Core\Entity\Sql\SqlContentEntityStorage->doLoadMultiple() (Line: 312) Drupal\Core\Entity\EntityStorageBase->loadMultiple() (Line: 513) Drupal\Core\Entity\EntityBase::loadMultiple() (Line: 2553) Drupal\api\Formatter::otherProjectsLink() (Line: 2706) Drupal\api\Formatter::preparePageListingVariables() (Line: 441) Drupal\api\Controller\OutputController->branchExplicitRoute() call_user_func_array() (Line: 123) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 637) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 124) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)Deprecated function: unserialize(): Passing null to parameter #1 ($data) of type string is deprecated in Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (line 474 of core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php).
Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (Line: 428) Drupal\Core\Entity\Sql\SqlContentEntityStorage->getFromStorage() (Line: 394) Drupal\Core\Entity\Sql\SqlContentEntityStorage->doLoadMultiple() (Line: 312) Drupal\Core\Entity\EntityStorageBase->loadMultiple() (Line: 513) Drupal\Core\Entity\EntityBase::loadMultiple() (Line: 2553) Drupal\api\Formatter::otherProjectsLink() (Line: 2706) Drupal\api\Formatter::preparePageListingVariables() (Line: 441) Drupal\api\Controller\OutputController->branchExplicitRoute() call_user_func_array() (Line: 123) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 637) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 124) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)Deprecated function: unserialize(): Passing null to parameter #1 ($data) of type string is deprecated in Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (line 474 of core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php).
Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (Line: 428) Drupal\Core\Entity\Sql\SqlContentEntityStorage->getFromStorage() (Line: 394) Drupal\Core\Entity\Sql\SqlContentEntityStorage->doLoadMultiple() (Line: 312) Drupal\Core\Entity\EntityStorageBase->loadMultiple() (Line: 513) Drupal\Core\Entity\EntityBase::loadMultiple() (Line: 2553) Drupal\api\Formatter::otherProjectsLink() (Line: 2706) Drupal\api\Formatter::preparePageListingVariables() (Line: 441) Drupal\api\Controller\OutputController->branchExplicitRoute() call_user_func_array() (Line: 123) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 637) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 124) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)Deprecated function: unserialize(): Passing null to parameter #1 ($data) of type string is deprecated in Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (line 474 of core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php).
Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (Line: 428) Drupal\Core\Entity\Sql\SqlContentEntityStorage->getFromStorage() (Line: 394) Drupal\Core\Entity\Sql\SqlContentEntityStorage->doLoadMultiple() (Line: 312) Drupal\Core\Entity\EntityStorageBase->loadMultiple() (Line: 513) Drupal\Core\Entity\EntityBase::loadMultiple() (Line: 2553) Drupal\api\Formatter::otherProjectsLink() (Line: 2706) Drupal\api\Formatter::preparePageListingVariables() (Line: 441) Drupal\api\Controller\OutputController->branchExplicitRoute() call_user_func_array() (Line: 123) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 637) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 124) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)Deprecated function: unserialize(): Passing null to parameter #1 ($data) of type string is deprecated in Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (line 474 of core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php).
Drupal\Core\Entity\Sql\SqlContentEntityStorage->mapFromStorageRecords() (Line: 428) Drupal\Core\Entity\Sql\SqlContentEntityStorage->getFromStorage() (Line: 394) Drupal\Core\Entity\Sql\SqlContentEntityStorage->doLoadMultiple() (Line: 312) Drupal\Core\Entity\EntityStorageBase->loadMultiple() (Line: 513) Drupal\Core\Entity\EntityBase::loadMultiple() (Line: 2553) Drupal\api\Formatter::otherProjectsLink() (Line: 2706) Drupal\api\Formatter::preparePageListingVariables() (Line: 441) Drupal\api\Controller\OutputController->branchExplicitRoute() call_user_func_array() (Line: 123) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 637) Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 124) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext() (Line: 97) Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181) Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76) Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53) Drupal\Core\StackMiddleware\Session->handle() (Line: 48) Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28) Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 32) Drupal\big_pipe\StackMiddleware\ContentLength->handle() (Line: 201) Drupal\page_cache\StackMiddleware\PageCache->fetch() (Line: 138) Drupal\page_cache\StackMiddleware\PageCache->lookup() (Line: 87) Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48) Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51) Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 36) Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 51) Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 741) Drupal\Core\DrupalKernel->handle() (Line: 19)- You are browsing documentation for drupal 9.5.x, which is not supported anymore. Read the updated version of this page for drupal 11.x (the latest version).
Services - 9.5.x - drupal
Introduction to services
A "service" (such as accessing the database, sending email, or translating user interface text) can be defined by a module or Drupal core. Defining a service means giving it a name and designating a default class to provide the service; ideally, there should also be an interface that defines the methods that may be called. Services are collected into the Dependency Injection Container, and can be overridden to use different classes or different instantiation by modules. See the Services and Dependency Injection Container topic for details.
Some services have tags, which are defined in the service definition. Tags are used to define a group of related services, or to specify some aspect of how the service behaves. See the Service Tags topic for more information.
See also
Services and Dependency Injection Container
File
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core/
core.api.php, line 905
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