ajax_alter_title.module

<?php

/**
 * @file
 * Primary module hooks for Ajax alter title module.
 */

use Drupal\Core\Ajax\AjaxResponse;
use Drupal\Core\Ajax\InvokeCommand;
use Drupal\Core\Ajax\HtmlCommand;
use Drupal\Core\Routing\RouteMatchInterface;

/**
 * Implements hook_help().
 */
function ajax_alter_title_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    case 'help.page.ajax_alter_title':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('This custom module is a great option for a Drupal website to announce concerts by using nodes.') . '</p>';
      $output .= '<p>' . t('Essentially, "ajax_alter_title" allows you to add the status of the concert to the title of its node.') . '</p>';
      $output .= '<p>' . t('The status can be "canceled", "postponed" or "sold out".') . '</p>';
      return $output;
    default:
  }
}

/**
 * Implements hook_form_FORM_ID_alter().
 */
function ajax_alter_title_form_node_page_edit_form_alter(&$form, $form_state, $form_id) {
  $form['canceled_title'] = [
    '#type' => 'button',
    '#value' => t('Add "CANCELED" prefix'),
    '#arg' => 'CANCELED',
    '#ajax' => [
      'callback' => 'ajax_alter_title_prefix',
      'wrapper' => 'edit-title-0-value',
      'event' => 'click',
      'progress' => [
        'type' => 'throbber',
        'message' => 'Updating title...'
      ]
    ]
  ];

  $form['postponed_title'] = [
    '#type' => 'button',
    '#value' => t('Add "POSTPONED" prefix'),
    '#arg' => 'POSTPONED',
    '#ajax' => [
      'callback' => 'ajax_alter_title_prefix',
      'wrapper' => 'edit-title-0-value',
      'event' => 'click',
      'progress' => [
        'type' => 'throbber',
        'message' => 'Updating title...'
      ]
    ]
  ];

  $form['sold_out_title'] = [
    '#type' => 'button',
    '#value' => t('Add "SOLD OUT" prefix'),
    '#arg' => 'SOLD OUT',
    '#ajax' => [
      'callback' => 'ajax_alter_title_prefix',
      'wrapper' => 'edit-title-0-value',
      'event' => 'click',
      'progress' => [
        'type' => 'throbber',
        'message' => 'Updating title...'
      ]
    ]
  ];

  $form['delete_title'] = [
    '#type' => 'button',
    '#value' => t('Delete current prefix'),
    '#arg' => 'delete',
    '#ajax' => [
      'callback' => 'ajax_alter_title_prefix',
      'wrapper' => 'edit-title-0-value',
      'event' => 'click',
      'progress' => [
        'type' => 'throbber',
        'message' => 'Deleting preffix...'
      ]
    ]
  ];

  $form['message_title'] = [
    '#type' => 'markup',
    '#markup' => '<div id="message-title"></div>',
  ];
}

/**
 * AJAX callback to add or delete prefixes.
 *
 * @param array &$form
 *   The form structure.
 * @param FormStateInterface &$form_state
 *   The current state of the form.
 *
 * @return \Drupal\Core\Ajax\AjaxResponse
 *   An AJAX response that updates the title field and displays a status message.
 */
function ajax_alter_title_prefix(&$form, &$form_state) {
  $response = new AjaxResponse();
  $current_title = $form['title']['widget'][0]['value']['#default_value'];
  $prefix = $form_state->getTriggeringElement()['#arg'];
  $default_options = ['CANCELED', 'POSTPONED', 'SOLD OUT'];

  if (in_array($prefix, $default_options)) {
    $parameters = ajax_alter_title_get_parameters($current_title, $prefix);
  }
  else {
    $parameters = ajax_alter_title_get_parameters_delete($current_title);
  }

  $response->addCommand(new InvokeCommand('#edit-title-0-value', 'val', [$parameters[0]]));
  $response->addCommand(new HtmlCommand('#message-title', $parameters[1]));
  return $response;
}

/**
 * Gets new title and message.
 *
 * @param string $current_title
 *   The current title of the node.
 * @param string $prefix
 *   The prefix to be added to the title.
 *
 * @return array
 *   An array containing:
 *   - The modified title (string).
 *   - A message indicating the status of the operation (string).
 */
function ajax_alter_title_get_parameters($current_title, $prefix) {
  if (!str_starts_with($current_title, $prefix)) {
    $current_title = preg_replace('/^(CANCELED \/|POSTPONED \/|SOLD OUT \/)\s*/', '', $current_title);
    $new_title = $prefix . ' / ' . $current_title;
    $message = '<p style="color:red;">"' . $prefix . '" has been added. Please, <b>save this node</b></p>';
  }
  else {
    $new_title = $current_title;
    $message = '<p style="color:red;">"' . $prefix . '" is already in the original title.</p>';
  }

  $result = [$new_title, $message];
  return $result;
}

/**
 * Gets new title and message when deleting any prefix.
 *
 * @param string $current_title
 *   The current title of the node.
 *
 * @return array
 *   An array containing:
 *   - The modified title (string).
 *   - A message indicating whether a prefix was removed or no change was needed (string).
 */
function ajax_alter_title_get_parameters_delete($current_title) {
  if (preg_match('/^(CANCELED|POSTPONED|SOLD OUT)/', $current_title)) {
    $new_title = preg_replace('/^(CANCELED \/|POSTPONED \/|SOLD OUT \/)\s*/', '', $current_title);
    $message = '<p style="color:red;">Prefix has been deleted. Please, <b>save this node</b></p>';
  }
  else {
    $new_title = $current_title;
    $message = '<p style="color:red;">There is no prefix in the original title.</p>';
  }

  $result = [$new_title, $message];
  return $result;
}