BackendPluginBase.php in Search API 8

Namespace

Drupal\search_api\Backend

File

src/Backend/BackendPluginBase.php

<?php

namespace Drupal\search_api\Backend;

use Drupal\Core\Messenger\MessengerInterface;
use Drupal\search_api\Entity\Server;
use Drupal\search_api\Item\ItemInterface;
use Drupal\search_api\LoggerTrait;
use Drupal\search_api\Query\QueryInterface;
use Drupal\search_api\SearchApiException;
use Drupal\search_api\IndexInterface;
use Drupal\search_api\Plugin\ConfigurablePluginBase;
use Drupal\search_api\ServerInterface;
use Drupal\search_api\Utility\FieldsHelper;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Defines a base class for backend plugins.
 *
 * Plugins extending this class need to define a plugin definition array through
 * annotation. These definition arrays may be altered through
 * hook_search_api_backend_info_alter(). The definition includes the following
 * keys:
 * - id: The unique, system-wide identifier of the backend class.
 * - label: The human-readable name of the backend class, translated.
 * - description: A human-readable description for the backend class,
 *   translated.
 *
 * A complete plugin definition should be written as in this example:
 *
 * @code
 * @SearchApiBackend(
 *   id = "my_backend",
 *   label = @Translation("My backend"),
 *   description = @Translation("Searches with SuperSearch™.")
 * )
 * @endcode
 *
 * @see \Drupal\search_api\Annotation\SearchApiBackend
 * @see \Drupal\search_api\Backend\BackendPluginManager
 * @see \Drupal\search_api\Backend\BackendInterface
 * @see plugin_api
 */
abstract class BackendPluginBase extends ConfigurablePluginBase implements BackendInterface {
  use LoggerTrait;

  /**
   * The server this backend is configured for.
   *
   * @var \Drupal\search_api\ServerInterface
   */
  protected $server;

  /**
   * The backend's server's ID.
   *
   * Used for serialization.
   *
   * @var string
   */
  protected $serverId;

  /**
   * The fields helper.
   *
   * @var \Drupal\search_api\Utility\FieldsHelper|null
   */
  protected $fieldsHelper;

  /**
   * The messenger.
   *
   * @var \Drupal\Core\Messenger\MessengerInterface|null
   */
  protected $messenger;

  /**
   * {@inheritdoc}
   */
  public function __construct(array $configuration, $plugin_id, array $plugin_definition) {
    if (($configuration['#server'] ?? NULL) instanceof ServerInterface) {
      $this
        ->setServer($configuration['#server']);
      unset($configuration['#server']);
    }
    parent::__construct($configuration, $plugin_id, $plugin_definition);
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {

    /** @var static $plugin */
    $plugin = parent::create($container, $configuration, $plugin_id, $plugin_definition);
    $plugin
      ->setFieldsHelper($container
      ->get('search_api.fields_helper'));
    $plugin
      ->setMessenger($container
      ->get('messenger'));
    return $plugin;
  }

  /**
   * Retrieves the fields helper.
   *
   * @return \Drupal\search_api\Utility\FieldsHelper
   *   The fields helper.
   */
  public function getFieldsHelper() {
    return $this->fieldsHelper ?: \Drupal::service('search_api.fields_helper');
  }

  /**
   * Sets the fields helper.
   *
   * @param \Drupal\search_api\Utility\FieldsHelper $fields_helper
   *   The new fields helper.
   *
   * @return $this
   */
  public function setFieldsHelper(FieldsHelper $fields_helper) {
    $this->fieldsHelper = $fields_helper;
    return $this;
  }

  /**
   * Retrieves the messenger.
   *
   * @return \Drupal\Core\Messenger\MessengerInterface
   *   The messenger.
   */
  public function getMessenger() {
    return $this->messenger ?: \Drupal::service('messenger');
  }

  /**
   * Sets the messenger.
   *
   * @param \Drupal\Core\Messenger\MessengerInterface $messenger
   *   The new messenger.
   *
   * @return $this
   */
  public function setMessenger(MessengerInterface $messenger) {
    $this->messenger = $messenger;
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public function setConfiguration(array $configuration) {
    parent::setConfiguration($configuration);
    if ($this->server && $this->server
      ->getBackendConfig() !== $configuration) {
      $this->server
        ->setBackendConfig($configuration);
    }
  }

  /**
   * {@inheritdoc}
   */
  public function getServer() {
    return $this->server;
  }

  /**
   * {@inheritdoc}
   */
  public function setServer(ServerInterface $server) {
    $this->server = $server;
    return $this;
  }

  /**
   * {@inheritdoc}
   */
  public function viewSettings() {
    return [];
  }

  /**
   * {@inheritdoc}
   */
  public function isAvailable() {
    return TRUE;
  }

  /**
   * {@inheritdoc}
   */
  public function getSupportedFeatures() {
    return [];
  }

  /**
   * {@inheritdoc}
   */
  public function supportsDataType($type) {
    return FALSE;
  }

  /**
   * {@inheritdoc}
   */
  public function postInsert() {
  }

  /**
   * {@inheritdoc}
   */
  public function preUpdate() {
  }

  /**
   * {@inheritdoc}
   */
  public function postUpdate() {
    return FALSE;
  }

  /**
   * {@inheritdoc}
   */
  public function preDelete() {
    try {
      $this
        ->getServer()
        ->deleteAllItems();
    } catch (SearchApiException $e) {
      $vars = [
        '%server' => $this
          ->getServer()
          ->label(),
      ];
      $this
        ->logException($e, '%type while deleting items from server %server: @message in %function (line %line of %file).', $vars);
      $this
        ->getMessenger()
        ->addError($this
        ->t('Deleting some of the items on the server failed. Check the logs for details. The server was still removed.'));
    }
  }

  /**
   * {@inheritdoc}
   */
  public function getBackendDefinedFields(IndexInterface $index) {
    return [];
  }

  /**
   * {@inheritdoc}
   */
  public function addIndex(IndexInterface $index) {
  }

  /**
   * {@inheritdoc}
   */
  public function updateIndex(IndexInterface $index) {
  }

  /**
   * {@inheritdoc}
   */
  public function removeIndex($index) {

    // Only delete the index's data if the index isn't read-only. (If only the
    // ID is given, we assume the index was read-only, to be on the safe side.)
    if ($index instanceof IndexInterface && !$index
      ->isReadOnly()) {
      $this
        ->deleteAllIndexItems($index);
    }
  }

  /**
   * {@inheritdoc}
   */
  public function getDiscouragedProcessors() {
    return [];
  }

  /**
   * Creates dummy field objects for the "magic" fields present for every index.
   *
   * @param \Drupal\search_api\IndexInterface $index
   *   The index for which to create the fields. (Needed since field objects
   *   always need an index set.)
   * @param \Drupal\search_api\Item\ItemInterface|null $item
   *   (optional) If given, an item whose data should be used for the fields'
   *   values.
   *
   * @return \Drupal\search_api\Item\FieldInterface[]
   *   An array of field objects for all "magic" fields, keyed by field IDs.
   */
  protected function getSpecialFields(IndexInterface $index, ItemInterface $item = NULL) {
    $field_info = [
      'type' => 'string',
      'original type' => 'string',
    ];
    $fields['search_api_id'] = $this
      ->getFieldsHelper()
      ->createField($index, 'search_api_id', $field_info);
    $fields['search_api_datasource'] = $this
      ->getFieldsHelper()
      ->createField($index, 'search_api_datasource', $field_info);
    $fields['search_api_language'] = $this
      ->getFieldsHelper()
      ->createField($index, 'search_api_language', $field_info);
    if ($item) {
      $fields['search_api_id']
        ->setValues([
        $item
          ->getId(),
      ]);
      $fields['search_api_datasource']
        ->setValues([
        $item
          ->getDatasourceId(),
      ]);
      $fields['search_api_language']
        ->setValues([
        $item
          ->getLanguage(),
      ]);
    }
    return $fields;
  }

  /**
   * Verifies that the given condition operator is valid for this backend.
   *
   * @param string $operator
   *   The operator in question.
   *
   * @throws \Drupal\search_api\SearchApiException
   *   Thrown if the operator is not known.
   *
   * @see \Drupal\search_api\Query\ConditionSetInterface::addCondition()
   */
  protected function validateOperator($operator) {
    switch ($operator) {
      case '=':
      case '<>':
      case '<':
      case '<=':
      case '>=':
      case '>':
      case 'IN':
      case 'NOT IN':
      case 'BETWEEN':
      case 'NOT BETWEEN':
        return;
    }
    throw new SearchApiException("Unknown operator '{$operator}' used in search query condition");
  }

  /**
   * Implements the magic __sleep() method.
   *
   * Prevents the server entity from being serialized.
   */
  public function __sleep() {
    if ($this->server) {
      $this->serverId = $this->server
        ->id();
    }
    $properties = array_flip(parent::__sleep());
    unset($properties['server']);
    unset($properties['logger']);
    return array_keys($properties);
  }

  /**
   * Implements the magic __wakeup() method.
   *
   * Reloads the server entity.
   */
  public function __wakeup() {
    parent::__wakeup();
    if ($this->serverId) {
      $this->server = Server::load($this->serverId);
      $this->serverId = NULL;
    }
  }

  /**
   * Retrieves the effective fulltext fields from the query.
   *
   * Automatically translates a NULL value in the query object to all fulltext
   * fields in the search index.
   *
   * If a specific backend supports any "virtual" fulltext fields not listed in
   * the index, it should override this method to add them, if appropriate.
   *
   * @param \Drupal\search_api\Query\QueryInterface $query
   *   The search query.
   *
   * @return string[]
   *   The fulltext fields in which to search for the search keys.
   *
   * @see \Drupal\search_api\Query\QueryInterface::getFulltextFields()
   */
  protected function getQueryFulltextFields(QueryInterface $query) {
    $fulltext_fields = $query
      ->getFulltextFields();
    $index_fields = $query
      ->getIndex()
      ->getFulltextFields();
    return $fulltext_fields === NULL ? $index_fields : array_intersect($fulltext_fields, $index_fields);
  }

}

Classes

Name	Description
BackendPluginBase	Defines a base class for backend plugins.