Same name and namespace in other branches
  1. 8.9.x core/lib/Drupal/Core/Form/FormBase.php \Drupal\Core\Form\FormBase
  2. 9 core/lib/Drupal/Core/Form/FormBase.php \Drupal\Core\Form\FormBase

Provides a base class for forms.

This class exists as a mid-point between dependency injection through ContainerInjectionInterface, and a less-structured use of traits which default to using the \Drupal accessor for service discovery.

To properly inject services, override create() and use the setters provided by the traits to inject the needed services.


public static function create($container) {
  $form = new static();
  // In this example we only need string translation so we use the
  // setStringTranslation() method provided by StringTranslationTrait.
  $form->setStringTranslation($container->get('string_translation'));
  return $form;
}

Alternately, do not use FormBase. A class can implement FormInterface, use the traits it needs, and inject services from the container as required.

Hierarchy

Expanded class hierarchy of FormBase

See also

\Drupal\Core\DependencyInjection\ContainerInjectionInterface

Related topics

142 files declare their use of FormBase
ActionAdminManageForm.php in core/modules/action/src/Form/ActionAdminManageForm.php
AddFormBase.php in core/modules/media_library/src/Form/AddFormBase.php
AjaxFormsTestAjaxElementsForm.php in core/modules/system/tests/modules/ajax_forms_test/src/Form/AjaxFormsTestAjaxElementsForm.php
AjaxFormsTestCommandsForm.php in core/modules/system/tests/modules/ajax_forms_test/src/Form/AjaxFormsTestCommandsForm.php
AjaxFormsTestImageButtonForm.php in core/modules/system/tests/modules/ajax_forms_test/src/Form/AjaxFormsTestImageButtonForm.php

... See full list

File

core/lib/Drupal/Core/Form/FormBase.php, line 44

Namespace

Drupal\Core\Form
View source
abstract class FormBase implements FormInterface, ContainerInjectionInterface {
  use DependencySerializationTrait;
  use LoggerChannelTrait;
  use MessengerTrait;
  use RedirectDestinationTrait;
  use StringTranslationTrait;

  /**
   * The request stack.
   *
   * @var \Symfony\Component\HttpFoundation\RequestStack
   */
  protected $requestStack;

  /**
   * The config factory.
   *
   * Subclasses should use the self::config() method, which may be overridden to
   * address specific needs when loading config, rather than this property
   * directly. See \Drupal\Core\Form\ConfigFormBase::config() for an example of
   * this.
   *
   * @var \Drupal\Core\Config\ConfigFactoryInterface
   */
  protected $configFactory;

  /**
   * The route match.
   *
   * @var \Drupal\Core\Routing\RouteMatchInterface
   */
  protected $routeMatch;

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static();
  }

  /**
   * {@inheritdoc}
   */
  public function validateForm(array &$form, FormStateInterface $form_state) {

    // Validation is optional.
  }

  /**
   * Retrieves a configuration object.
   *
   * This is the main entry point to the configuration API. Calling
   * @code $this->config('my_module.admin') @endcode will return a configuration
   * object in which the my_module module can store its administrative settings.
   *
   * @param string $name
   *   The name of the configuration object to retrieve. The name corresponds to
   *   a configuration file. For @code \Drupal::config('my_module.admin') @endcode,
   *   the config object returned will contain the contents of my_module.admin
   *   configuration file.
   *
   * @return \Drupal\Core\Config\ImmutableConfig
   *   A configuration object.
   */
  protected function config($name) {
    return $this
      ->configFactory()
      ->get($name);
  }

  /**
   * Gets the config factory for this form.
   *
   * When accessing configuration values, use $this->config(). Only use this
   * when the config factory needs to be manipulated directly.
   *
   * @return \Drupal\Core\Config\ConfigFactoryInterface
   */
  protected function configFactory() {
    if (!$this->configFactory) {
      $this->configFactory = $this
        ->container()
        ->get('config.factory');
    }
    return $this->configFactory;
  }

  /**
   * Sets the config factory for this form.
   *
   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
   *   The config factory.
   *
   * @return $this
   */
  public function setConfigFactory(ConfigFactoryInterface $config_factory) {
    $this->configFactory = $config_factory;
    return $this;
  }

  /**
   * Resets the configuration factory.
   */
  public function resetConfigFactory() {
    $this->configFactory = NULL;
  }

  /**
   * Gets the request object.
   *
   * @return \Symfony\Component\HttpFoundation\Request
   *   The request object.
   */
  protected function getRequest() {
    if (!$this->requestStack) {
      $this->requestStack = \Drupal::service('request_stack');
    }
    return $this->requestStack
      ->getCurrentRequest();
  }

  /**
   * Gets the route match.
   *
   * @return \Drupal\Core\Routing\RouteMatchInterface
   */
  protected function getRouteMatch() {
    if (!$this->routeMatch) {
      $this->routeMatch = \Drupal::routeMatch();
    }
    return $this->routeMatch;
  }

  /**
   * Sets the request stack object to use.
   *
   * @param \Symfony\Component\HttpFoundation\RequestStack $request_stack
   *   The request stack object.
   *
   * @return $this
   */
  public function setRequestStack(RequestStack $request_stack) {
    $this->requestStack = $request_stack;
    return $this;
  }

  /**
   * Gets the current user.
   *
   * @return \Drupal\Core\Session\AccountInterface
   *   The current user.
   */
  protected function currentUser() {
    return \Drupal::currentUser();
  }

  /**
   * Returns a redirect response object for the specified route.
   *
   * @param string $route_name
   *   The name of the route to which to redirect.
   * @param array $route_parameters
   *   (optional) Parameters for the route.
   * @param array $options
   *   (optional) An associative array of additional options.
   * @param int $status
   *   (optional) The HTTP redirect status code for the redirect. The default is
   *   302 Found.
   *
   * @return \Symfony\Component\HttpFoundation\RedirectResponse
   *   A redirect response object that may be returned by the controller.
   */
  protected function redirect($route_name, array $route_parameters = [], array $options = [], $status = 302) {
    $options['absolute'] = TRUE;
    return new RedirectResponse(Url::fromRoute($route_name, $route_parameters, $options)
      ->toString(), $status);
  }

  /**
   * Returns the service container.
   *
   * This method is marked private to prevent sub-classes from retrieving
   * services from the container through it. Instead,
   * \Drupal\Core\DependencyInjection\ContainerInjectionInterface should be used
   * for injecting services.
   *
   * @return \Symfony\Component\DependencyInjection\ContainerInterface
   *   The service container.
   */
  private function container() {
    return \Drupal::getContainer();
  }

  /**
   * Gets the logger for a specific channel.
   *
   * This method exists for backward-compatibility between FormBase and
   * LoggerChannelTrait. Use LoggerChannelTrait::getLogger() instead.
   *
   * @param string $channel
   *   The name of the channel. Can be any string, but the general practice is
   *   to use the name of the subsystem calling this.
   *
   * @return \Psr\Log\LoggerInterface
   *   The logger for the given channel.
   */
  protected function logger($channel) {
    return $this
      ->getLogger($channel);
  }

}

Members

Name Modifierssort descending Type Description Overrides
FormBase::container private function Returns the service container.
FormBase::config protected function Retrieves a configuration object.
FormBase::configFactory protected function Gets the config factory for this form. 2
FormBase::getRequest protected function Gets the request object.
FormBase::getRouteMatch protected function Gets the route match.
FormBase::currentUser protected function Gets the current user.
FormBase::redirect protected function Returns a redirect response object for the specified route.
FormBase::logger protected function Gets the logger for a specific channel.
LoggerChannelTrait::getLogger protected function Gets the logger for a specific channel.
RedirectDestinationTrait::getDestinationArray protected function Prepares a 'destination' URL query parameter for use with \Drupal\Core\Url.
RedirectDestinationTrait::getRedirectDestination protected function Returns the redirect destination service.
StringTranslationTrait::t protected function Translates a string to the current language or to a given language.
StringTranslationTrait::formatPlural protected function Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals protected function Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation protected function Gets the string translation service.
FormBase::$requestStack protected property The request stack. 1
FormBase::$configFactory protected property The config factory. 2
FormBase::$routeMatch protected property The route match.
DependencySerializationTrait::$_serviceIds protected property
DependencySerializationTrait::$_entityStorages protected property
LoggerChannelTrait::$loggerFactory protected property The logger channel factory service.
MessengerTrait::$messenger protected property The messenger. 10
RedirectDestinationTrait::$redirectDestination protected property The redirect destination service. 1
StringTranslationTrait::$stringTranslation protected property The string translation service. 3
FormBase::validateForm public function Form validation handler. Overrides FormInterface::validateForm 51
FormBase::setConfigFactory public function Sets the config factory for this form.
FormBase::resetConfigFactory public function Resets the configuration factory.
FormBase::setRequestStack public function Sets the request stack object to use.
DependencySerializationTrait::__sleep public function 2
DependencySerializationTrait::__wakeup public function 2
LoggerChannelTrait::setLoggerFactory public function Injects the logger channel factory.
MessengerTrait::setMessenger public function Sets the messenger.
MessengerTrait::messenger public function Gets the messenger. 10
RedirectDestinationTrait::setRedirectDestination public function Sets the redirect destination service.
StringTranslationTrait::setStringTranslation public function Sets the string translation service to use. 1
FormInterface::getFormId public function Returns a unique string identifying the form. 223
FormInterface::buildForm public function Form constructor. 189
FormInterface::submitForm public function Form submission handler. 209
FormBase::create public static function Instantiates a new instance of this class. Overrides ContainerInjectionInterface::create 88