AjaxFormsTestImageButtonForm.php

<?php

namespace Drupal\ajax_forms_test\Form;

use Drupal\ajax_forms_test\Callbacks;
use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;

/**
 * Form builder: Builds a form that has image button with an ajax callback.
 *
 * @internal
 */
class AjaxFormsTestImageButtonForm extends FormBase {
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'ajax_forms_test_image_button_form';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $object = new Callbacks();
        $form['image_button'] = [
            '#type' => 'image_button',
            '#name' => 'image_button',
            '#src' => 'core/misc/icons/787878/cog.svg',
            '#attributes' => [
                'alt' => $this->t('Edit'),
            ],
            '#op' => 'edit',
            '#ajax' => [
                'callback' => [
                    $object,
                    'imageButtonCallback',
                ],
            ],
            '#suffix' => '<div id="ajax_image_button_result">Image button not pressed yet.</div>',
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        // No submit code needed.
    }

}