Anders Grendstadbakk

WordPress SEO and relative links

I really like WordPress SEO, it’s a nice plugin that does everything I need for SEO. But for long I have had a problem with the sitemap feature. My posts did not show up in the post-sitemap.

I did not look into it anymore until today, when I looked through webmaster tools and figured I should get everything to work.

I opened class-sitemaps.php in the WordPress SEO plugin and started to go through the code.

At line 818 I found this snippet:

if ( false === strpos( $url['loc'], $this->home_url ) ) {

For some reason this continue always triggered. At first I did not see what the problem was, since all my posts have urls. But then I realized (as you probably have guessed from the title) that all of them where relative links.

And WordPress SEO treats them as external links.

The solution

The fix was quite easy. WordPress SEO have a alter hook right before this check, so with a small function in my functions.php I re-added the domain part of the url.

function andeersg_fix_urls($url, $post) {
  if (substr($url, 0, 1) == '/') {
    return home_url() . $url;
  else {
    return $url;
add_filter('wpseo_xml_sitemap_post_url', 'andeersg_fix_urls', 10,  2);

I do a small check to see that the first character is a forward slash so I don’t “fix” actual external urls if there are some of those.

And with that snippet enabled the sitemaps work again.

The actual problem

I have a plugin called Root Relative URLs enabled, and that plugin removes the domain part from all urls.

I found this blog entry from Yoast, the team behind WordPress SEO that talks about how relative urls are not good. So I guess that may be the reason they treat relative urls this way.

I’m actually not sure why I have that plugin enabled, but I guess it has something to do with local development and broken/wrong image links.

Anyhow, disabling plugins that create relative urls will fix this problem, or you could use my code snippet. I will continue to use it until I know why I have that relative links plugin enabled.