A collection of WordPress snippets

wordpress-snippets.php

<?php
// functions.php

/**
 * Remove language dropdown from WordPress Admin login screen.
 */
add_filter('login_display_language_dropdown', '__return_false');

/**
 * Disable XML-RPC by default.
 */
add_filter('xmlrpc_enabled', '__return_false');
remove_action('xmlrpc_rsd_apis', 'rest_output_rsd');
remove_action('template_redirect', 'rest_output_link_header', 11);

/**
 * Disable 'users' route from REST API for security reason.
 *
 * @method rest_authentication_errors
 *
 * @param  mixed $access [authentication response].
 * @return mixed [authentication error or default].
 */
function mnet_rest_authentication_handler($access) {
  // define user permission.
  $has_permission = false;
  if ( $user_id = get_current_user_id() ) {
    $user = get_user_by('id', $user_id);
    $allowed_roles = array('administrator', 'editor', 'author');
    $has_permission = ( is_array($user->roles) && !empty(array_intersect($allowed_roles, $user->roles)) );
  }

  // get the current rest route.
  $rest_route = $GLOBALS['wp']->query_vars['rest_route'];
  if ( !empty($rest_route) || $rest_route != '/' ) {
    $rest_route = untrailingslashit($rest_route);
  }

  // check for invalid access.
  if ( strpos($rest_route, 'users') !== false && !$has_permission ) {
    return new WP_Error(
      'rest_cannot_access',
      esc_html('You cannot access this REST API route.'),
      ['status' => rest_authorization_required_code()]
    );
  }

  return $access;
}
add_filter('rest_authentication_errors', 'mnet_rest_authentication_handler', 99, 1);

/**
 * Configure manually the SMTP parameters needed for wp_mail.
 *
 * @link https://developer.wordpress.org/reference/hooks/phpmailer_init/#comment-4298
 * @param  PHPMailer $phpmailer [default PHP Mailer instance].
 */
function mnet_phpmailer_smtp_config($phpmailer) {
  if ( !is_object($phpmailer) ) {
    $phpmailer = (object) $phpmailer;
  }

  $phpmailer->Mailer     = 'smtp';
  $phpmailer->SMTPAuth   = true;
  $phpmailer->Host       = SMTP_HOST;
  $phpmailer->Port       = SMTP_PORT;
  $phpmailer->Username   = SMTP_USER;
  $phpmailer->Password   = SMTP_PASS;
  $phpmailer->SMTPSecure = SMTP_SECURE;

  $from_name = get_bloginfo('name');
  $phpmailer->From       = SMTP_USER;
  $phpmailer->FromName   = "Noreply {$from_name}";
}
add_action('phpmailer_init', 'mnet_phpmailer_smtp_config', 11);

/**
 * Trying to get a retina logo URL by attachment ID, if available.
 *
 * @param  int    $attachment_id
 * @return string $retina_logo_url
 */
function mnet_retina_logo($attachment_id) {
  $retina_logo_url = '';
  $attachment_name = wp_basename( wp_get_attachment_url($attachment_id) );
  $retina_attachment_title = str_replace('.png', '@2x', $attachment_name);
  if ( $retina_attachment = get_page_by_title($retina_attachment_title, OBJECT, 'attachment') ) {
    $retina_logo_url .= wp_get_attachment_url($retina_attachment->ID);
  }
  return $retina_logo_url;
}

/**
 * Make sure to disable browser telephone format detection on iOS/Safari.
 *
 * @see    https://developer.apple.com/library/archive/documentation/AppleApplications/Reference/SafariHTMLRef/Articles/MetaTags.html#//apple_ref/doc/uid/TP40008193-SW1
 * @link   https://stackoverflow.com/questions/226131/how-to-disable-phone-number-linking-in-mobile-safari
 *
 * @return void
 */
function mnet_telephone_format_detection_meta() {
  echo "<meta name=\"format-detection\" content=\"telephone=no\" />\n";
}
add_action('wp_head', 'mnet_telephone_format_detection_meta', 11);

/**
 * Make sure to save and load ACF fields across different environments.
 *
 * @return void
 */
function mnet_acf_save_fields($path) {
  $path = get_stylesheet_directory() . '/acf_fields';
  return $path;
}
add_filter('acf/settings/save_json', 'mnet_acf_save_fields', 11, 1);
function mnet_acf_load_fields($paths) {
  if (isset($paths[0])) {
    unset($paths[0]);
  }
  $paths[] = get_stylesheet_directory() . '/acf_fields';
  return $paths;
}
add_filter('acf/settings/load_json', 'mnet_acf_load_fields', 11, 1);