AjaxFormTrait.php

<?php

namespace Drupal\ctools\Form;

use Drupal\Component\Serialization\Json;
use Drupal\Component\Utility\NestedArray;

/**
 * Provides helper methods for using an AJAX modal.
 */
trait AjaxFormTrait {
    
    /**
     * Gets attributes for use with an AJAX modal.
     *
     * @return array
     *   The array of attributes.
     */
    public static function getAjaxAttributes() {
        return [
            'class' => [
                'use-ajax',
            ],
            'data-dialog-type' => 'modal',
            'data-dialog-options' => Json::encode([
                'width' => 'auto',
            ]),
        ];
    }
    
    /**
     * Gets attributes for use with an add button AJAX modal.
     *
     * @return array
     *   The array of attributes.
     */
    public static function getAjaxButtonAttributes() {
        return NestedArray::mergeDeep(AjaxFormTrait::getAjaxAttributes(), [
            'class' => [
                'button',
                'button--small',
                'button-action',
            ],
        ]);
    }

}