Can't remove front from permalinks for custom taxonomy category page

Question

I've made a custom post type called 'portfolio' and a custom taxonomy called 'portfolio-categorie'. While I see the new categories in my pages, I have a problem removing the 'front' from the url structure. My preferred url would be domain.com/portfolio/category-name/ or domain.com/portfolio/categorie/catergory-name would also be an option.

In my permalink settings I have this as a structure (used for blog): /blog/%postname%/

When I visit a custom taxonomy category page, I get a 404 error page. I did rewrite the permalinks.

If I change the with_front to 'with_front' => false WordPress returns a page but with the url /blog/portfolio/portfolio-name/

What am I doing wrong?

My code so far:

function custom_post_type() {

    $labels = array(
        'name'                  => _x( 'Portfolio', 'Post Type General Name', 'text_domain' ),
        'singular_name'         => _x( 'Project', 'Post Type Singular Name', 'text_domain' ),
        'menu_name'             => __( 'Portfolio', 'text_domain' ),
        'name_admin_bar'        => __( 'Portfolio', 'text_domain' ),
        'archives'              => __( 'Item Archives', 'text_domain' ),
        'parent_item_colon'     => __( 'Parent Item:', 'text_domain' ),
        'all_items'             => __( 'Alle Projecten', 'text_domain' ),
        'add_new_item'          => __( 'Voeg nieuw Project toe', 'text_domain' ),
        'add_new'               => __( 'Voeg toe', 'text_domain' ),
        'new_item'              => __( 'Nieuw Project', 'text_domain' ),
        'edit_item'             => __( 'Bewerk Project', 'text_domain' ),
        'update_item'           => __( 'Pas Project aan', 'text_domain' ),
        'view_item'             => __( 'Bekijk Project', 'text_domain' ),
        'search_items'          => __( 'Doorzoek Project', 'text_domain' ),
        'not_found'             => __( 'Niet gevonden', 'text_domain' ),
        'not_found_in_trash'    => __( 'Niet gevonden in de prullenmand', 'text_domain' ),
        'featured_image'        => __( 'Project Hoofdafbeelding', 'text_domain' ),
        'set_featured_image'    => __( 'Stel Hoofdafbeelding in', 'text_domain' ),
        'remove_featured_image' => __( 'Verwijder hoofdafbeelding', 'text_domain' ),
        'use_featured_image'    => __( 'Gebruik als hoofdafbeelding', 'text_domain' ),
        'insert_into_item'      => __( 'Voeg toe aan project', 'text_domain' ),
        'uploaded_to_this_item' => __( 'Geupload naar dit project', 'text_domain' ),
        'items_list'            => __( 'Project lijst', 'text_domain' ),
        'items_list_navigation' => __( 'Project navigatie', 'text_domain' ),
        'filter_items_list'     => __( 'Filter project lijst', 'text_domain' ),
    );
    $args = array(
        'label'                 => __( 'Portfolio', 'text_domain' ),
        'description'           => __( 'Recente projecten', 'text_domain' ),
        'labels'                => $labels,
        'supports'              => array( 'title', 'editor', 'thumbnail', ),
        'hierarchical'          => true,
        'public'                => true,
        'show_ui'               => true,
        'show_in_menu'          => true,
        'menu_position'         => 5,
        'menu_icon'             => 'dashicons-images-alt',
        'show_in_admin_bar'     => true,
        'show_in_nav_menus'     => true,
        'can_export'            => true,
        'has_archive'           => true,
        'exclude_from_search'   => false,
        'publicly_queryable'    => true,
        'capability_type'       => 'page',
        'rewrite'               => array( 'with_front' => false ),
    );
    register_post_type( 'portfolio', $args );
}
add_action( 'init', 'custom_post_type', 0 );


function portfolio_custom_taxonomy() {

  $labels = array(
    'name' => _x( 'Categorieën', 'taxonomy general name' ),
    'singular_name' => _x( 'Categorie', 'taxonomy singular name' ),
    'search_items' =>  __( 'Zoek categorieën' ),
    'all_items' => __( 'Alle categorieën' ),
    'parent_item' => __( 'Bovenliggende categorie' ),
    'parent_item_colon' => __( 'Bovenliggende categorie:' ),
    'edit_item' => __( 'Bewerk categorie' ), 
    'update_item' => __( 'Update categorie' ),
    'add_new_item' => __( 'Nieuwe categorie toevoegen' ),
    'new_item_name' => __( 'Nieuwe categorie' ),
    'menu_name' => __( 'Categorieën' ),
  );    

  register_taxonomy('portfolio-categorie', 'portfolio', array(
    'hierarchical' => true,
    'labels' => $labels,
    'show_ui' => true,
    'show_admin_column' => true,
    'query_var' => true,
    'rewrite' => array( 'slug' => 'portfolio', 'with_front' => false ),
  ));
}

add_action( 'init', 'portfolio_custom_taxonomy', 0 );

Any help would be greatly appreciated!

Answer 1

To get the URL like example.tld/portfolio/PORTFOLIO-CATEGORY-NAME/PORTFOLIO-NAME/ do the following.

Change rewrite for the custom post type to

'rewrite' => array(
    'slug'       => 'portfolio/%portfolio-categorie%',
    'with_front' => false
),

Change rewrite for the custom taxonomy to

'rewrite' => array(
    'with_front' => false
),

Use post_type_link filter to replace %portfolio-categorie% with the actual taxonomy term:

add_filter( 'post_type_link', 'my_portfolio_permalink', 10, 4 );

function my_portfolio_permalink( $post_link, $post, $leavename, $sample ) {
    if ( false !== strpos( $post_link, '%portfolio-categorie%' ) ) {

        $portfolio_cat_term = get_the_terms( $post->ID, 'portfolio-categorie' );

        if ( !empty( $portfolio_cat_term ) ) {
            $post_link = str_replace( '%portfolio-categorie%', array_pop( $portfolio_cat_term )->
        slug, $post_link );
        } else {
            $post_link = str_replace( '%portfolio-categorie%', 'uncategorized', $post_link );
        }
    }
    return $post_link;
}