class EntityReference

class EntityReference extends DisplayPluginBase {
    
    /**
     * {@inheritdoc}
     */
    protected $usesAJAX = FALSE;
    
    /**
     * {@inheritdoc}
     */
    protected $usesPager = FALSE;
    
    /**
     * {@inheritdoc}
     */
    protected $usesAttachments = FALSE;
    
    /**
     * The database connection.
     *
     * @var \Drupal\Core\Database\Connection
     */
    protected $connection;
    
    /**
     * The id field alias.
     */
    // phpcs:ignore Drupal.NamingConventions.ValidVariableName.LowerCamelName
    public string $id_field_alias;
    
    /**
     * Constructs a new EntityReference object.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin ID for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\Core\Database\Connection $connection
     *   The database connection.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, Connection $connection) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->connection = $connection;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('database'));
    }
    
    /**
     * {@inheritdoc}
     */
    protected function defineOptions() {
        $options = parent::defineOptions();
        // Force the style plugin to 'entity_reference_style' and the row plugin to
        // 'fields'.
        $options['style']['contains']['type'] = [
            'default' => 'entity_reference',
        ];
        $options['defaults']['default']['style'] = FALSE;
        $options['row']['contains']['type'] = [
            'default' => 'entity_reference',
        ];
        $options['defaults']['default']['row'] = FALSE;
        // Set the display title to an empty string (not used in this display type).
        $options['title']['default'] = '';
        $options['defaults']['default']['title'] = FALSE;
        return $options;
    }
    
    /**
     * {@inheritdoc}
     */
    public function optionsSummary(&$categories, &$options) {
        parent::optionsSummary($categories, $options);
        // Disable 'title' so it won't be changed from the default set in
        // \Drupal\views\Plugin\views\display\EntityReference::defineOptions.
        unset($options['title']);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getType() {
        return 'entity_reference';
    }
    
    /**
     * {@inheritdoc}
     */
    public function execute() {
        return $this->view
            ->render($this->display['id']);
    }
    
    /**
     * Builds the view result as a renderable array.
     *
     * @return array
     *   Renderable array or empty array.
     */
    public function render() {
        if (!empty($this->view->result) && $this->view->style_plugin
            ->evenEmpty()) {
            return $this->view->style_plugin
                ->render($this->view->result);
        }
        return [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function usesExposed() {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function query() {
        if (!empty($this->view->live_preview)) {
            return;
        }
        // Make sure the id field is included in the results.
        $id_field = $this->view->storage
            ->get('base_field');
        $id_table = $this->view->storage
            ->get('base_table');
        $this->id_field_alias = $this->view->query
            ->addField($id_table, $id_field);
        $options = $this->getOption('entity_reference_options') ?? [];
        // The entity_reference_options are typically set during a call to
        // Drupal\views\Plugin\EntityReferenceSelection\ViewsSelection::initializeView().
        // If any entity_reference_options are not yet set, we apply the same
        // default values that would typically be added by that method.
        $default_options = [
            'match' => NULL,
            'match_operator' => 'CONTAINS',
            'limit' => 0,
            'ids' => NULL,
        ];
        $options += $default_options;
        // Restrict the autocomplete options based on what's been typed already.
        if (isset($options['match'])) {
            $style_options = $this->getOption('style');
            $value = $this->connection
                ->escapeLike($options['match']);
            if ($options['match_operator'] !== '=') {
                $value = $value . '%';
                if ($options['match_operator'] != 'STARTS_WITH') {
                    $value = '%' . $value;
                }
            }
            // Multiple search fields are ORed together.
            $conditions = $this->view->query
                ->getConnection()
                ->condition('OR');
            // Build the condition using the selected search fields.
            foreach ($style_options['options']['search_fields'] as $field_id) {
                if (!empty($field_id)) {
                    // Get the table and field names for the checked field.
                    $field_handler = $this->view->field[$field_id];
                    $table_alias = $this->view->query
                        ->ensureTable($field_handler->table, $field_handler->relationship);
                    $field_alias = $this->view->query
                        ->addField($table_alias, $field_handler->realField);
                    $field = $this->view->query->fields[$field_alias];
                    // Add an OR condition for the field.
                    $conditions->condition($field['table'] . '.' . $field['field'], $value, 'LIKE');
                }
            }
            $this->view->query
                ->addWhere(0, $conditions);
        }
        // Add an IN condition for validation.
        if (!empty($options['ids'])) {
            $this->view->query
                ->addWhere(0, $id_table . '.' . $id_field, $options['ids'], 'IN');
        }
        $this->view
            ->setItemsPerPage($options['limit']);
    }
    
    /**
     * {@inheritdoc}
     */
    public function validate() {
        $errors = parent::validate();
        // Verify that search fields are set up.
        $style = $this->getOption('style');
        if (!isset($style['options']['search_fields'])) {
            $errors[] = $this->t('Display "@display" needs a selected "Search fields" value to work properly. See the settings for the "Entity Reference list" format.', [
                '@display' => $this->display['display_title'],
            ]);
        }
        else {
            // Verify that the search fields used actually exist.
            $fields = array_keys($this->handlers['field']);
            foreach ($style['options']['search_fields'] as $field_alias => $enabled) {
                if ($enabled && !in_array($field_alias, $fields)) {
                    $errors[] = $this->t('Display "@display" uses field %field as search field, but the field is no longer present. See the settings for the Entity Reference list format.', [
                        '@display' => $this->display['display_title'],
                        '%field' => $field_alias,
                    ]);
                }
            }
        }
        return $errors;
    }

}