Replace Wordpress %postname% suffix with %postid%?

Question

I run a news site and there's a Wordpress permalink issue that I have been wondering. Now, Wordpress will add an incremental numeric suffix to duplicate %postname% regardless of the directory structure.

For example, wordpress will add a "-2" suffix to the permalink regardless if the structure is domain.com/2016/04/03/news-title or domain.com/category/news-title-%post_id% when it detects a duplicate.

I initially believe that Wordpress would not add the suffix automatically after appending a %post-id% to the end of the permalink but that is not the case.

What I'm trying to achieve (without Wordpress meddling with the %postname%) is the following:

• domain.com/2016/04/03/news-title-44956 (assuming the numbers behind is the %post_id)
• domain.com/2017/05/06/news-title-55957

or

• domain.com/2016/04/03/44956/news-title
• domain.com/2017/05/06/55957/news-title

I hate the idea that I won't be able to use the same title with a different content a year later (or many years later) even though the permalink directory is vastly different by then.

Is there any way I can add hooks or temporarily modifying the Wordpress core to fix this or at least get Wordpress to automatically append the %post-id% instead of an incremental number when it detects a duplicate permalink?

Answer 1

I suppose you could filter wp_unique_post_slug and have it return the original slug for posts, but I'm not sure what kind of side-effects this may have:

add_filter( 'wp_unique_post_slug', function( $slug, $post_id, $post_status, $post_type, $post_parent, $original_slug ) {
    if ( $post_type == 'post' )
        $slug = $original_slug;

    return $slug;
}, 10, 6 );

And here's how you would append the post ID instead of -2:

add_filter( 'wp_unique_post_slug', function( $slug, $post_id, $post_status, $post_type, $post_parent, $original_slug ) {
    if ( $post_type == 'post' && $slug != $original_slug )
        $slug = preg_replace( '#\-[0-9]+$#', '-' . $post_id, $slug );

    return $slug;
}, 10, 6 );