The adjacent_posts_rel_link_wp_head() WordPress PHP function displays relational links for the posts adjacent to the current post on single post pages. It is meant to be attached to actions like ‘wp_head’. Do not call this directly in plugins or theme templates. For a similar function, see also adjacent_posts_rel_link().
Usage
This function is typically used in your theme’s functions.php file. It’s attached to the ‘wp_head’ action, so it automatically prints the relational links in the head section of your site’s HTML. It doesn’t take any parameters and doesn’t return anything.
add_action( 'wp_head', 'adjacent_posts_rel_link_wp_head' );
Parameters
This function does not take any parameters.
More information
See WordPress Developer Resources: adjacent_posts_rel_link_wp_head()
Examples
Basic Usage
In this example, we’re adding the function to the ‘wp_head’ action. This will print the adjacent post links in the head section of your site’s HTML.
// Add the function to the 'wp_head' action add_action( 'wp_head', 'adjacent_posts_rel_link_wp_head' );
Removing the Function
In this example, we’re removing the function from the ‘wp_head’ action. This will stop the adjacent post links from being printed in the head section.
// Remove the function from the 'wp_head' action remove_action( 'wp_head', 'adjacent_posts_rel_link_wp_head' );
Conditional Usage
In this example, we’re only adding the function to the ‘wp_head’ action if the current page is a single post.
if ( is_single() ) {
// Add the function to the 'wp_head' action
add_action( 'wp_head', 'adjacent_posts_rel_link_wp_head' );
}
Function Check
In this example, we’re checking if the function exists before adding it to the ‘wp_head’ action. This is a good practice in case the function gets deprecated in a future version of WordPress.
if ( function_exists( 'adjacent_posts_rel_link_wp_head' ) ) {
// Add the function to the 'wp_head' action
add_action( 'wp_head', 'adjacent_posts_rel_link_wp_head' );
}
Using with a Custom Action
In this example, we’re creating a custom action that will run the function. This gives us more control over when and where the function is called.
// Create a custom action that runs the function do_action( 'my_custom_action' ); // Add the function to our custom action add_action( 'my_custom_action', 'adjacent_posts_rel_link_wp_head' );