ListStringItem.php

<?php

namespace Drupal\options\Plugin\Field\FieldType;

use Drupal\Core\Field\Attribute\FieldType;
use Drupal\Core\Field\FieldFilteredMarkup;
use Drupal\Core\Field\FieldStorageDefinitionInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Render\Element;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\TypedData\DataDefinition;

/**
 * Plugin implementation of the 'list_string' field type.
 */
class ListStringItem extends ListItemBase {
    
    /**
     * {@inheritdoc}
     */
    public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
        $properties['value'] = DataDefinition::create('string')->setLabel(new TranslatableMarkup('Text value'))
            ->addConstraint('Length', [
            'max' => 255,
        ])
            ->setRequired(TRUE);
        return $properties;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function schema(FieldStorageDefinitionInterface $field_definition) {
        return [
            'columns' => [
                'value' => [
                    'type' => 'varchar',
                    'length' => 255,
                ],
            ],
            'indexes' => [
                'value' => [
                    'value',
                ],
            ],
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    protected function allowedValuesDescription() {
        $description = '<p>' . $this->t('The name will be used in displayed options and edit forms.');
        $description .= '<br/>' . $this->t('The value is automatically generated machine name of the name provided and will be the stored value.');
        $description .= '</p>';
        $description .= '<p>' . $this->t('Allowed HTML tags in labels: @tags', [
            '@tags' => FieldFilteredMarkup::displayAllowedTags(),
        ]) . '</p>';
        return $description;
    }
    
    /**
     * {@inheritdoc}
     */
    protected static function validateAllowedValue($option) {
        if (mb_strlen($option) > 255) {
            return new TranslatableMarkup('Allowed values list: each key must be a string at most 255 characters long.');
        }
    }
    
    /**
     * {@inheritdoc}
     */
    protected static function castAllowedValue($value) {
        return (string) $value;
    }
    
    /**
     * {@inheritdoc}
     */
    public function storageSettingsForm(array &$form, FormStateInterface $form_state, $has_data) {
        $element = parent::storageSettingsForm($form, $form_state, $has_data);
        // Improve user experience by using an automatically generated machine name.
        foreach (Element::children($element['allowed_values']['table']) as $delta => $row) {
            $element['allowed_values']['table'][$delta]['item']['key']['#type'] = 'machine_name';
            $element['allowed_values']['table'][$delta]['item']['key']['#machine_name'] = [
                'exists' => [
                    static::class,
                    'exists',
                ],
            ];
            $element['allowed_values']['table'][$delta]['item']['key']['#process'] = array_merge([
                [
                    static::class,
                    'processAllowedValuesKey',
                ],
            ], \Drupal::service('plugin.manager.element_info')->getInfoProperty('machine_name', '#process', []));
            // Remove #element_validate from the machine name so that any value can be
            // used as a key, while keeping the widget's behavior for generating
            // defaults the same.
            $element['allowed_values']['table'][$delta]['item']['key']['#element_validate'] = [];
        }
        return $element;
    }
    
    /**
     * Sets the machine name source to be the label.
     */
    public static function processAllowedValuesKey(array &$element) : array {
        $parents = $element['#parents'];
        array_pop($parents);
        $parents[] = 'label';
        $element['#machine_name']['source'] = $parents;
        // Override the default description which is not applicable to this use of
        // the machine name element given that it allows users to manually enter
        // characters usually not allowed in machine names.
        if (!isset($element['#description'])) {
            $element['#description'] = '';
        }
        return $element;
    }
    
    /**
     * Checks for existing keys for allowed values.
     */
    public static function exists() : bool {
        // Without access to the current form state, we cannot know if a given key
        // is in use. Return FALSE in all cases.
        return FALSE;
    }

}