WordPress Complete - Sixth Edition

Registering and using a custom taxonomy

Just to follow the example given a while ago with our custom post type for books, let's now create a custom taxonomy. Essentially, you might not want to mix book categories and post categories, so we are going to create a custom taxonomy named Book Categories. Add the following code to your functions.php file:

function build_taxonomies() { 
  register_taxonomy( 
    'book_category', 
    'book', 
    array( 
      'hierarchical' => true, 
      'label' => 'Book Category', 
      'query_var' => true, 
      'rewrite' => array('slug' => 'available-books') 
    ) 
  ); 
} 
add_action('init', 'build_taxonomies', 0);

Like the register_post_type() function, the register_taxonomy() function allows you to register a new taxonomy within WordPress. You can read up ...