AjaxTestMessageCommandForm.php

<?php

namespace Drupal\ajax_test\Form;

use Drupal\Core\Ajax\AjaxResponse;
use Drupal\Core\Ajax\MessageCommand;
use Drupal\Core\Form\FormInterface;
use Drupal\Core\Form\FormStateInterface;

/**
 * Form for testing AJAX MessageCommand.
 *
 * @internal
 */
class AjaxTestMessageCommandForm implements FormInterface {
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'ajax_test_message_command_form';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $form['alternate-message-container'] = [
            '#type' => 'container',
            '#id' => 'alternate-message-container',
        ];
        $form['button_default'] = [
            '#type' => 'submit',
            '#name' => 'makedefaultmessage',
            '#value' => 'Make Message In Default Location',
            '#ajax' => [
                'callback' => '::makeMessageDefault',
            ],
        ];
        $form['button_alternate'] = [
            '#type' => 'submit',
            '#name' => 'makealternatemessage',
            '#value' => 'Make Message In Alternate Location',
            '#ajax' => [
                'callback' => '::makeMessageAlternate',
            ],
        ];
        $form['button_warning'] = [
            '#type' => 'submit',
            '#name' => 'makewarningmessage',
            '#value' => 'Make Warning Message',
            '#ajax' => [
                'callback' => '::makeMessageWarning',
            ],
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function validateForm(array &$form, FormStateInterface $form_state) {
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
    }
    
    /**
     * Callback for testing MessageCommand with default settings.
     *
     * @return \Drupal\Core\Ajax\AjaxResponse
     *   The AJAX response.
     */
    public function makeMessageDefault() {
        $response = new AjaxResponse();
        return $response->addCommand(new MessageCommand('I am a message in the default location.'));
    }
    
    /**
     * Callback for testing MessageCommand using an alternate message location.
     *
     * @return \Drupal\Core\Ajax\AjaxResponse
     *   The AJAX response.
     */
    public function makeMessageAlternate() {
        $response = new AjaxResponse();
        return $response->addCommand(new MessageCommand('I am a message in an alternate location.', '#alternate-message-container', [], FALSE));
    }
    
    /**
     * Callback for testing MessageCommand with warning status.
     *
     * @return \Drupal\Core\Ajax\AjaxResponse
     *   The AJAX response.
     */
    public function makeMessageWarning() {
        $response = new AjaxResponse();
        return $response->addCommand(new MessageCommand('I am a warning message in the default location.', NULL, [
            'type' => 'warning',
            'announce' => '',
        ]));
    }

}