Custom Taxonomy Archives Page Errors

Question

I have successfully created a custom taxonomy 'Authors' for quotations by adding the following code in my child theme's functions.php:

/** * Add custom taxonomies */
function add_custom_taxonomies() {
    // Add new "Authors" taxonomy to Posts
    register_taxonomy('author', 'post', array(
        'hierarchical' => true,
        'labels' => array( 'name' => _x( 'Authors', 'taxonomy general name' ),
        'singular_name' => _x( 'author', 'taxonomy singular name' ),
        'search_items' => __( 'Search Authors' ),
        'all_items' => __( 'All Authors' ),
        'parent_item' => __( 'Parent author' ),
        'parent_item_colon' => __( 'Parent author:' ),
        'edit_item' => __( 'Edit author' ),
        'update_item' => __( 'Update author' ),
        'add_new_item' => __( 'Add New author' ),
        'new_item_name' => __( 'New author Name' ),
        'menu_name' => __( 'Authors' ), ),
        'rewrite' => array(
              'slug' => 'authors',
              'with_front' => false,
              'hierarchical' => true
        ),
    ));
}
add_action( 'init', 'add_custom_taxonomies', 0 );

Then I have added an 'author' from my WP admin. Next I added a post with author 'Abdul Kalam', an eminent scientist from India. The post is clearly displaying the hyperlinked author name (added some code in parent theme's single.php).

Next I duplicated parent theme's archive.php to taxonomy-authors.php to list all the 'authors'. Also created another duplicate of archive.php to taxonomy-authors-abdul-kalam.php to show all posts that are tagged with author abdul kalam.

Problem is, I get a 404 error page whenever I browse to example.com/authors/ or to example.com/authors/abdul-kalam/. I have flushed permalinks some 10-15 times but no luck.

What am I doing wrong?

PS: I have tried other Taxonomy names such as Personalities which doesn't work either! While 'author' may already exist and may not work, 'authors' should work.

Answer 1

The problem is this:

register_taxonomy('author', 'post', array( //tax args here... ));

The first argument, which is taxonomy name, you've set to author. WordPress uses that value as the taxonomy query var if a value isn't explicitly declared. When this taxonomy is queried, author is used to pass the requested term slug to the query.

The problem with that is that WordPress already uses author to query for users via their ID. Visiting those term pages results in WordPress trying to query for posts where user ID is 0, which will always be a 404 (any non-numeric string is interpreted as invalid and becomes integer 0).

Either change the name to something else:

register_taxonomy('something_unique', 'post', array( //tax args here... ));

Or, explicitly set query_var to something other than author.

register_taxonomy('author', 'post', array(
    'query_var' => 'something_unique',
    // the rest of your tax args...
));