Issue #2830403 by szato, amarlata, bgilhome, mayurgajar, grathbone,...

<?php

namespace Drupal\classy_paragraphs\Plugin\EntityReferenceSelection;

use Drupal\Core\Entity\Plugin\EntityReferenceSelection\DefaultSelection;

use Drupal\Core\Form\FormStateInterface;

use Drupal\classy_paragraphs\Entity\ClassyParagraphsStyle;

/**

 * Plugin implementation of the Entity Reference Selection plugin.

 *

 * @EntityReferenceSelection(

 *   id = "classy_paragraphs",

 *   label = @Translation("Classy paragraphs"),

 *   entity_types = {"classy_paragraphs_style"},

 *   group = "classy_paragraphs",

 *   weight = 5

 * )

 */

class ClassyParagraphsSelection extends DefaultSelection {

  /**

   * @inheritDoc

   */

  public function defaultConfiguration() {

    return parent::defaultConfiguration() + [

      'filter' => [

        'type' => '_none',

        'negate' => FALSE,

      ],

      'sort' => [

        'field' => '_none',

      ],

    ];

  }

  /**

   * {@inheritdoc}

   */

  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {

    $bundles = ClassyParagraphsStyle::loadMultiple();

    $bundle_options = [];

    foreach ($bundles as $bundle_name => $bundle_info) {

      $bundle_options[$bundle_name] = $bundle_info->label();

    }

    natsort($bundle_options);

    $form['filter']['type'] = [

      '#type' => 'select',

      '#title' => $this->t('Filter by'),

      '#options' => [

        '_none' => $this->t('- None -'),

        'target_bundles' => $this->t('Classy styles'),

        'starts_with' => $this->t('Machine name'),

      ],

      '#ajax' => TRUE,

      '#limit_validation_errors' => [],

      '#default_value' => $this->configuration['filter']['type'],

    ];

    if ($this->configuration['filter']['type'] != '_none') {

      if ($this->configuration['filter']['type'] === 'target_bundles') {

        $form['filter']['target_bundles'] = [

          '#type' => 'checkboxes',

          '#title' => $this->t('Classy paragraphs styles'),

          '#options' => $bundle_options,

          '#default_value' => isset($this->configuration['filter']['target_bundles']) ? (array) $this->configuration['filter']['target_bundles'] : [],

          '#description' => t('If no classes are selected, all will be allowed, independent on negate filter.'),

          '#required' => FALSE,

        ];

        $form['filter']['negate'] = [

          '#type' => 'checkbox',

          '#title' => $this->t('Negate filter'),

          '#default_value' => $this->configuration['filter']['negate'],

          '#description' => t('Possible to filter newly added classes dynamically without updating the field config.'),

          '#required' => FALSE,

        ];

      }

      if ($this->configuration['filter']['type'] === 'starts_with') {

        $form['filter']['starts_with'] = [

          '#type' => 'textfield',

          '#title' => $this->t('Classy paragraphs machine name starts with'),

          '#default_value' => isset($this->configuration['filter']['starts_with']) ? $this->configuration['filter']['starts_with'] : '',

          '#description' => t('You can filter for matching machine names.') . ' ' . t('Possible to filter newly added classes dynamically without updating the field config.'),

          '#required' => FALSE,

        ];

      }

      $form['sort']['field'] = [

        '#type' => 'select',

        '#title' => $this->t('Sort by'),

        '#options' => [

          '_none' => $this->t('- None -'),

          'id' => $this->t('Machine name'),

          'label' => $this->t('Label'),

        ],

        '#ajax' => TRUE,

        '#limit_validation_errors' => [],

        '#default_value' => $this->configuration['sort']['field'],

      ];

      if ($this->configuration['sort']['field'] != '_none') {

        // Merge-in default values.

        $this->configuration['sort'] += [

          'direction' => 'ASC',

        ];

        $form['sort']['direction'] = [

          '#type' => 'select',

          '#title' => $this->t('Sort direction'),

          '#required' => TRUE,

          '#options' => [

            'ASC' => $this->t('Ascending'),

            'DESC' => $this->t('Descending'),

          ],

          '#default_value' => $this->configuration['sort']['direction'],

        ];

      }

    }

    return $form;

  }

  /**

   * {@inheritdoc}

   */

  protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS') {

    $query = parent::buildEntityQuery($match, $match_operator);

    // Used for autocomplete.

    if (isset($match)) {

      $query->condition('label', $match, $match_operator);

    }

    // Filter by machine name.

    if (!empty($this->configuration['filter']['starts_with'])) {

      $query->condition('id', $this->configuration['filter']['starts_with'], 'STARTS_WITH');

    }

    // Filter by paragraphs type/bundle name.

    if (!empty($this->configuration['filter']['target_bundles'])) {

      $query->condition('id', $this->configuration['filter']['target_bundles'], $this->configuration['filter']['negate'] ? 'NOT IN' : 'IN');

    }

    // Add the sort option.

    if (!empty($this->configuration['sort'])) {

      $sort_settings = $this->configuration['sort'];

      if ($sort_settings['field'] != '_none') {

        $query->sort($sort_settings['field'], $sort_settings['direction']);

      }

    }

    $query->addTag('classy');

    return $query;

  }

}