Using WordPress ‘language_attributes’ PHP filter

by

The language_attributes WordPress PHP Filter allows you to modify the language attributes displayed in the ‘html’ tag.

Usage

add_filter('language_attributes', 'your_custom_function', 10, 2);

function your_custom_function($output, $doctype) {
  // your custom code here
  return $output;
}

Parameters

  • $output (string) – A space-separated list of language attributes.
  • $doctype (string) – The type of HTML document (xhtml|html).

More information

See WordPress Developer Resources: language_attributes

Examples

Add a custom language attribute

Add a custom language attribute called “data-custom-lang”.

add_filter('language_attributes', 'add_custom_language_attribute', 10, 2);

function add_custom_language_attribute($output, $doctype) {
  $output .= ' data-custom-lang="en-US"';
  return $output;
}

Change the language attribute

Change the language attribute value to “en-GB”.

add_filter('language_attributes', 'change_language_attribute', 10, 2);

function change_language_attribute($output, $doctype) {
  $output = str_replace('en-US', 'en-GB', $output);
  return $output;
}

Remove the language attribute

Remove the language attribute from the ‘html’ tag.

add_filter('language_attributes', 'remove_language_attribute', 10, 2);

function remove_language_attribute($output, $doctype) {
  $output = '';
  return $output;
}

Add a custom attribute based on the post’s language

Add a custom attribute called “data-post-lang” based on the post’s language.

add_filter('language_attributes', 'add_post_language_attribute', 10, 2);

function add_post_language_attribute($output, $doctype) {
  global $post;
  $post_language = get_post_meta($post->ID, 'post_language', true);
  $output .= ' data-post-lang="' . esc_attr($post_language) . '"';
  return $output;
}

Change the doctype to XHTML

Change the doctype of the ‘html’ tag to XHTML.

add_filter('language_attributes', 'change_doctype_to_xhtml', 10, 2);

function change_doctype_to_xhtml($output, $doctype) {
  if ($doctype == 'html') {
    $doctype = 'xhtml';
  }
  $output = preg_replace('/(<!DOCTYPE\s+html)/i', '<!DOCTYPE ' . $doctype, $output);
  return $output;
}