How to set hreflang correctly? (as ISO639-1 compliant value)

The CMS Questions
1

I am using the following code within <head> to set a few hreflang links:

  <?php foreach($kirby->languages() as $language): ?>
  <link 
      rel="alternate"
      hreflang="<?php echo html($language->locale(LC_ALL)); ?>"
      href="<?= $page->url($language->code()); ?>" >
  <?php endforeach; ?>

When I validate my site through the W3C Validator, this throws an error:

Bad value en_us for attribute hreflang on element link: The language subtag en_us is not a valid language subtag.

For my understanding the hreflang attribute has to be a ISO 639-1 compliant value.

Is there a way to achieve this?

2

I think it should be “en-US” instead of “en_us”

3

Is there a way to return the correct value directly or do I have to convert the returned values from $language->locale(LC_ALL) myself?

4

Do you need the explicit region? The hreflang attributes accepts both simple languade codes like de, en etc. as well as en-gb, en-us etc.

For the simple code, you can simply use $language->code().

2 Likes
5

This seems to be a great solution, thanks!

I built a slightly different solution that seems to work at least for the language my site supports:

$languageCode = strtolower(str_replace("_", "-", $language->locale(LC_ALL)));

All the best, Martin