url rewriting - Add %post_id% to slug of custom post type and prevent the "unique slug" thing that WP does?

I have a custom post type called "equipment". I would like the permalink structure to be:

example/equipment/%post_id%-slug

I specifically want it to use a dash and not a slash (i.e. - "id-slug" not "id/slug"). Every possible solution I've found from googling has used slashes and I just can't get it to work with a dash.

I also want to prevent WordPress from adding on the additional number if there's two posts with the same title. Example:

example/equipment/45-awesomeness
and
example/equipment/46-awesomeness-2

I think the solution is to use add_rewrite_rule, but I'm a bit confused with the regex stuff.

The following code did work to replace the post name with the id in the slug:

function equipment_links($post_link, $post = 0) {
    if($post->post_type === 'equipment') {
        return home_url('equipment/' . $post->ID . '');
    }
    else{
        return $post_link;
    }
}
add_filter('post_type_link', 'equipment_links', 1, 3);


function equipment_rewrites_init(){
    add_rewrite_rule('equipment/([0-9]+)?$', 'index.php?post_type=equipment&p=$matches[1]', 'top');
}
add_action('init', 'equipment_rewrites_init');

It did return a url of "example/equipment/123", but I would like to tack on "-post_name" to the end of that "123".

I have a custom post type called "equipment". I would like the permalink structure to be:

example.com/equipment/%post_id%-slug

I specifically want it to use a dash and not a slash (i.e. - "id-slug" not "id/slug"). Every possible solution I've found from googling has used slashes and I just can't get it to work with a dash.

I also want to prevent WordPress from adding on the additional number if there's two posts with the same title. Example:

example.com/equipment/45-awesomeness
and
example.com/equipment/46-awesomeness-2

I think the solution is to use add_rewrite_rule, but I'm a bit confused with the regex stuff.

The following code did work to replace the post name with the id in the slug:

function equipment_links($post_link, $post = 0) {
    if($post->post_type === 'equipment') {
        return home_url('equipment/' . $post->ID . '');
    }
    else{
        return $post_link;
    }
}
add_filter('post_type_link', 'equipment_links', 1, 3);


function equipment_rewrites_init(){
    add_rewrite_rule('equipment/([0-9]+)?$', 'index.php?post_type=equipment&p=$matches[1]', 'top');
}
add_action('init', 'equipment_rewrites_init');

It did return a url of "example.com/equipment/123", but I would like to tack on "-post_name" to the end of that "123".

• custom-post-types
• url-rewriting
• urls
• slug

Share Improve this question edited Jan 31, 2019 at 4:35 Malachi Draven asked Jan 31, 2019 at 4:29 Malachi DravenMalachi Draven 2311 silver badge55 bronze badges 1

• Maybe taking a look here wp_unique_post_slug helps you out, or an example as answer here from Steven Harris. – Charles Commented Jan 31, 2019 at 17:03

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2 Answers 2

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I don't have much experience with coding rewrites, but could you just add $post->post_name into your return statement?

return home_url('equipment/' . $post->ID . '-' . $post->post_name );

There are a few other ways to change the permalinks that I have used that may also help you:

1. The easiest way to change your permalink structure is probably to use a custom structure by going to the admin menu, settings > permalinks. Select custom structure and set it to /%post_id%-%postname%/
2. If you are looking to edit the permalink structure for the specific post type without touching any code or another post type, I would suggest downloading a plugin like "Custom Post Type Permalinks" or "Simple Post Type Permalinks" both by Toro_Unit.

In regards to the unique identifier, you want to remove at the end.. I don't have that answer. However, if you are willing to use a .htacess rewrite instead of php, you may want to give this a try:

https://stackoverflow.com/questions/14635438/remove-trailing-number-from-url-via-htaccess

Get the result for permalink structure for your custom post type "equipment" and prevent WordPress from appending a number to the slug if there are posts with the same title, you can use the post_type_link filter hook and customize the permalink generation process.

Add code in your theme functions.php file or in a custom plugin

// Modify the permalink structure for the custom post type "equipment"
function custom_equipment_permalink($permalink, $post) {
    // Make sure it's our custom post type
    if ('equipment' === $post->post_type) {
        // Get the post ID
        $post_id = $post->ID;

        // Get the post name (slug)
        $post_slug = $post->post_name;

        // Construct the permalink with the desired format
        $new_permalink = home_url("/equipment/{$post_id}-{$post_slug}");

        return $new_permalink;
    }

    return $permalink;
}
add_filter('post_type_link', 'custom_equipment_permalink', 10, 2);



// Prevent WordPress from appending a number to the slug if there are posts with the same title
function prevent_duplicate_post_slugs($slug, $post_ID, $post_status, $post_type) {
    // Make sure it's our custom post type
    if ('equipment' === $post_type) {
        global $wpdb;

        // Get the number of posts with the same slug
        $check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_type = %s AND ID != %d LIMIT 1";
        $post_name_check = $wpdb->get_var($wpdb->prepare($check_sql, $slug, $post_type, $post_ID));

        // If there are posts with the same slug, append a number to make it unique
        if ($post_name_check || -1 !== intval(get_page_by_path($slug, OBJECT, $post_type))) {
            $suffix = 2;
            do {
                $alt_post_name = $slug . '-' . $suffix;
                $post_name_check = $wpdb->get_var($wpdb->prepare($check_sql, $alt_post_name, $post_type, $post_ID));
                $suffix++;
            } while ($post_name_check);

            return $alt_post_name;
        }
    }

    return $slug;
}
add_filter('wp_unique_post_slug', 'prevent_duplicate_post_slugs', 10, 4);