| 7 system.api.php | hook_html_head_alter(&$head_elements) |
| 8 system.api.php | hook_html_head_alter(&$head_elements) |
Alter XHTML HEAD tags before they are rendered by drupal_get_html_head().
Elements available to be altered are only those added using drupal_add_html_head_link() or drupal_add_html_head(). CSS and JS files are handled using drupal_add_css() and drupal_add_js(), so the head links for those files will not appear in the $head_elements array.
Parameters
$head_elements: An array of renderable elements. Generally the values of the #attributes array will be the most likely target for changes.
Related topics
File
- modules/
system/ system.api.php, line 3698 - Hooks provided by Drupal core and the System module.
Code
<?php
function hook_html_head_alter(&$head_elements) {
foreach ($head_elements as $key => $element) {
if (isset($element['#attributes']['rel']) && $element['#attributes']['rel'] == 'canonical') {
// I want a custom canonical url.
$head_elements[$key]['#attributes']['href'] = mymodule_canonical_url();
}
}
}
?>
Comments
Unlike other hooks, this is a
Unlike other hooks, this is a theme hook, so implementation is like:
<?phpTHEME_NAME_html_head_alter(&$head_elements) {
[...]
}
?>
At least, that was the only way to get this one to actually do anything.
It can perfectly reside in a module, but it's called from the theming layer and will alter the theme it's called from.