Include taxonomy slug in url?

Question

I have the following custom post-type and custom taxonomy setup:

add_action( 'init', 'create_post_type' );
function create_post_type() {
    register_post_type( 'system',
        array(
            'labels' => array(
                'name' => __( 'Systems' ),
                'singular_name' => __( 'System' )
            ),
        'capability_type' => 'post',
        'supports' => array('title','editor','comments'),   
        'public' => true,
        'has_archive' => true,
        'rewrite' => array( 'slug' => 'system' ),
        )
    );
}

function news_init() {
    register_taxonomy(
        'system',
        'system',
        array(
            'label' => __( 'Product Category' ),
            'sort' => true,
            'hierarchical' => true,
            'args' => array( 'orderby' => 'term_order' ),
            'rewrite' => array( 'slug' => 'product-category' )
        )
    );  
}
add_action( 'init', 'news_init' );

Is it possible to include the custom taxonomy name in the URL?

At present when I goto a custom post the URL looks like this:

http://www.domain/product-category/(post-name)/

How can I make it look like the following?

http://www.domain/(category-slug)/(post-name)/

Answer 1

This can be a bit challenging for WordPress, because it wouldn't know whether you are referring to post, page or taxonomy. Nevertheless, rename your taxonomy to something like product_category and try changing the slug in your post type arguments to system/%product_category%, and slug in your taxonomy arguments to just system. WordPress should now handle /system/your-product-category/post-name/

Out of the box WordPress doesn't recognize the permalink structure tag %product_category%, so we need to declare it:

function filter_post_type_permalink($link, $post)
{
    if ($post->post_type != 'system')
        return $link;

    if ($cats = get_the_terms($post->ID, 'product_category'))
        $link = str_replace('%product_category%', array_pop($cats)->slug, $link);
    return $link;
}
add_filter('post_type_link', 'filter_post_type_permalink', 10, 2);

NOTES:

1. This will just grab the first product category for the post ordered by name.
2. There still may be some 404 errors, if pages, posts etc., have same names.

Answer 2

First off DO NOT USE SAME POST TYPE & TAXONOMY, In fact, you do not even need to register a taxonomy since you require category. Use the following code:

add_action( 'init', 'create_post_type' );
function create_post_type() {
    register_post_type( 'system',
        array(
            'labels' => array(
                'name' => __( 'Systems' ),
                'singular_name' => __( 'System' )
            ),
        'capability_type' => 'post',
        'supports' => array('title','editor','comments'),   
        'public' => true,
        'has_archive' => true,
        'rewrite' => array( 'slug' => '%category%' ),
        'taxonomies' => array('category')
        )
    );
}

Now you will have categories available for use with your 'system' post type. Also observe that I have changed the value of slug. Now next hook up with filter post_type_link , this is used to replace '%category%' with the slug of category. Use the following code:

function replace_system_type_category( $post_link, $id = 0 ){
    $post = get_post($id);  
    if ( is_object( $post ) ){
        $terms = wp_get_object_terms( $post->ID, 'category' );
        if( $terms ){
            return str_replace( '%category%' , $terms[0]->slug , $post_link );
        }
    }
    return $post_link;  
}
add_filter( 'post_type_link', 'replace_system_type_category', 1, 3 );

The above code with replace %category% with the slug of category as required by you. You can use the code with custom taxonomy however do not use 'system' for both post type and taxonomy.

Answer 3

This is what i tested locally and it displays the taxonomy type name you create in the settings page the code adds in the permalink on taxonomy archive pages.

add_action( 'init', 'wpsites_create_custom_taxonomy_types' );
function wpsites_create_custom_taxonomy_types() {

register_taxonomy( 'system-type', 'system',
    array(
        'labels' => array(
            'name'          => _x( 'Types', 'taxonomy general name', 'wpsites' ),
            'add_new_item'  => __( 'Add New System Type', 'wpsites' ),
            'new_item_name' => __( 'New System Type', 'wpsites' ),
        ),
        'exclude_from_search' => true,
        'has_archive'         => true,
        'hierarchical'        => true,
        'rewrite'             => array( 'slug' => 'system-type', 'with_front' => false ),
        'show_ui'             => true,
        'show_tagcloud'       => false,
    ));

}



add_action( 'init', 'wpsites_system_custom_post_type' );
function wpsites_system_custom_post_type() {

register_post_type( 'system',
    array(
        'labels' => array(
            'name'          => __( 'System', 'wpsites' ),
            'singular_name' => __( 'System', 'wpsites' ),
        ),
        'has_archive'  => true,
        'hierarchical' => true,
        'menu_icon'    => 'dashicons-admin-network',
        'public'       => true,
        'rewrite'      => array( 'slug' => 'system', 'with_front' => false ),
        'supports'     => array( 'title', 'editor', 'author', 'thumbnail', 'excerpt', 'trackbacks', 'custom-fields', 'revisions', 'page-attributes' ),
        'taxonomies'   => array( 'system-type' ),

    ));

}