permalink not working on custom post and category

Question

I am trying to add wordpress custom post type and category in wordpress

   add_action( 'init', 'work_register' );   

    function work_register() {   

    $labels = array( 
        'name' => _x('Work', 'post type general name'), 
        'singular_name' => _x('Work Item', 'post type singular name'), 
        'add_new' => _x('Add New', 'work item'), 
        'add_new_item' => __('Add New Work Item'), 
        'edit_item' => __('Edit Work Item'), 
        'new_item' => __('New Work Item'), 

        'view_item' => __('View Work Item'), 
        'search_items' => __('Search Work'), 
        'not_found' => __('Nothing found'), 
        'not_found_in_trash' => __('Nothing found in Trash'), 
        'parent_item_colon' => '' 
    );   

    $args = array( 
        'labels' => $labels, 
        'public' => true, 
        'publicly_queryable' => true, 
        'show_ui' => true, 
        'query_var' => true, 
        'menu_icon' => get_stylesheet_directory_uri() . '/article16.png', 
        'rewrite' => array( 'slug' => 'work', 'with_front'=> false ), 
        'capability_type' => 'post', 
        'hierarchical' => true,
        'has_archive' => true,  
        'menu_position' => null, 
        'supports' => array('title','editor','thumbnail') 
    );   

    register_post_type( 'work' , $args ); 

    register_taxonomy( 'categories', array('work'), array(
        'hierarchical' => true, 
        'label' => 'Categories', 
        'singular_label' => 'Category', 
        'rewrite' => array( 'slug' => 'categories', 'with_front'=> false )
        )
    );

    register_taxonomy_for_object_type( 'categories', 'work' );
}

My permalink structure is:

/%category%/%postname%/

When I am adding from post it is giving me link

  /category/postname

but when I am adding from custom post, it is giving me only

 /postname 

I want /category/postname in custom post also

Please suggest where I am wrong

Answer 1

Change your rewrite to add the work post type query var:

'rewrite' => array('slug' => 'work/%categories%')

Then filter post_type_link to insert the selected categories into the permalink:

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

There are also plugins like Custom Post Type Permalinks that can do this for you.