metatag-8.x-1.x-dev/metatag_favicons/metatag_favicons.module

<?php

/**
 * @file
 * Custom hook implementations for Metatag Favicons.
 */

use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\StringTranslation\TranslatableMarkup;

/**
 * Implements hook_help().
 */
function metatag_favicons_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    // Main module help for the metatag_favicons module.
    case 'help.page.metatag_favicons':
      $output = '';
      $output .= '<h3>' . (string) new TranslatableMarkup('About') . '</h3>';
      $output .= '<p>' . (string) new TranslatableMarkup('Provides support for many different favicons.') . '</p>';
      return $output;

    default:
  }
}

/**
 * Implements hook_page_attachments_alter().
 */
function metatag_favicons_page_attachments_alter(array &$attachments) {
  // Check html_head_link on attached tags in head.
  if (!isset($attachments['#attached']['html_head_link'])) {
    return;
  }

  // Remove the default shortcut icon if one was set by Metatag.
  $valid_meta_tags = ['shortcut icon', 'shortcut_icon', 'icon'];
  foreach ($attachments['#attached']['html_head'] as $element) {
    if (isset($element[1]) && in_array($element[1], $valid_meta_tags)) {
      foreach ($attachments['#attached']['html_head_link'] as $key => $value) {
        if (isset($value[0]['rel']) && in_array($value[0]['rel'], $valid_meta_tags)) {
          unset($attachments['#attached']['html_head_link'][$key]);
        }
      }
    }
  }
}