Home Page rel="canonical"

Question

We created a home page as node/1850 which is specified in /admin/config/system/site-information. When I look at the generated code, I see:

<link rel="canonical" href="/node/1850" />

This results in Google listing the url of the home page as https://dom.ain/node/1850 which is not what we want.

What is the best way to correct this? I believe the following is correct.

<link rel="canonical" href="/" />

Answer 1

You can use metatag module to adjust metatags like these.

After installing you can visit the settings page /admin/config/search/metatag and there is a specific set of metatags to adjust for front page. Edit those settings and adjust canonical but I believe by default it sets this to [site:url] which should be OK.

Alternatively or if you don't want to install a module just for this you can do it using hook_preprocess_html in your THEMENAME.theme

function THEMENAME_preprocess_html(&$variables) {
  //if not front page do nothing
  if(! \Drupal::service('path.matcher')->isFrontPage())
    return ;

  //unset if set
  foreach ($variables['page']['#attached']['html_head'] as $key => &$value) {
    if ($value[0]['#tag'] == 'link' && $value[0]['#attributes']['rel'] == 'canonical') {
      unset($variables['page']['#attached']['html_head'][$key]);
      break;
    }
  }

  //add canonical
  $canonical = [
    '#type' => 'html_tag',
    '#tag' => 'link',
    '#attributes' => [
      'rel' => 'canonical',
      'href' => '/',
    ],
  ];
  $variables['page']['#attached']['html_head'][] = [$canonical, 'canonical'];  
}