How to use pre_wp_unique_post_slug filter in WordPress

Let’s dive into the pre_wp_unique_post_slug filter hook in WordPress. This hook is a lifesaver when you want to short-circuit the unique slug generation and return the value you prefer. You just need to register it using add_filter in your theme’s functions.php file or a custom WordPress plugin. It’s always wise to go the plugin route to avoid issues during theme updates.

Here’s how to get started:

Parameters

Below are the 6 parameters required to use this hook:

• $override_slug : (string|null) Short-circuit return value.
• $slug : (string) The desired slug (post_name).
• $post_ID : (int) Post ID.
• $post_status : (string) The post status.
• $post_type : (string) Post type.
• $post_parent : (int) Post parent ID.

Live Example

apply_filters( 'pre_wp_unique_post_slug', string|null $override_slug, string $slug, int $post_ID, string $post_status, string $post_type, int $post_parent )

Below are three examples of how you can use this hook:

Example 1: Basic Usage

In this example, we’ll define a function weplugins_modify_pre_wp_unique_post_slug_defaults that takes the 6 parameters and registers the filter.

function weplugins_modify_pre_wp_unique_post_slug_defaults($override_slug, $slug, $post_ID, $post_status, $post_type, $post_parent) { 
    // Update the $override_slug variable according to your website requirements and return this variable. 
    return $override_slug; 
}
// add the filter
add_filter( "pre_wp_unique_post_slug", "weplugins_modify_pre_wp_unique_post_slug_defaults", 10, 6 );

Example 2: Conditional Slug Modification

This example conditionally modifies the slug based on post type.

function weplugins_modify_pre_wp_unique_post_slug_conditional($override_slug, $slug, $post_ID, $post_status, $post_type, $post_parent) {
    if ($post_type == 'custom_post') {
        $override_slug = 'custom-' . $slug;
    }
    return $override_slug;
}
// add the filter
add_filter( "pre_wp_unique_post_slug", "weplugins_modify_pre_wp_unique_post_slug_conditional", 10, 6 );

Example 3: Removing the Filter

To remove a hook callback, use the example below. Make sure to provide the same callback function name, priority, and number of arguments while removing the hook callback.

remove_filter( "pre_wp_unique_post_slug", "weplugins_modify_pre_wp_unique_post_slug_defaults", 10, 6 );

Contact Us

If you’re having any trouble using this hook or need customization, please contact our team, and we’d be happy to assist you.