Why is my working Custom Taxonomy not in get_taxonomies array?

Question

I've created a custom taxonomy. It's working just as expected, aside from it is not showing in the get_taxonomies array. get_terms function returns an invalid taxonomy error.

I want to use get_terms to loop through the Double India Pale Ales and print each name for a select box.

Here is the code used to register it.

add_action( 'init', 'double_ipa_init' );

function double_ipa_init()  {
    register_taxonomy(
        'double-ipa',
        array (
            0 => 'post',
            1 => 'page',
        ),
        array(
            'hierarchical' => true,
            'label' => 'Double IPAs',
            'show_ui' => true,
            'query_var' => true,
            'rewrite' => array(
                'slug' => 'double-ipa'
            ),
        'singular_label' => 'Double IPA'
        )
    );
}

This code is in a plugin, and is on Multisite.

Thanks in advance for your help.

Answer 1

The Invalid Taxonomy error will be raised by the function get_terms(). You're registring your taxonomy on the init action hook. Therefore you have to call your get_terms() function on the same or a later hook.

Try this snippet. It should display all term names of your taxonomy, regardless if the term is empty.

add_action('init', 'wpse29164_registerTaxonomy');
function wpse29164_registerTaxonomy() {
    $args = array(
        'hierarchical' => true,
        'label' => 'Double IPAs',
        'show_ui' => true,
        'query_var' => true,
        'rewrite' => array(
            'slug' => 'double-ipa'
        ),
        'singular_label' => 'Double IPA'
    );

    register_taxonomy('double-ipa', array('post', 'page'), $args);

    $terms = get_terms('double-ipa', array('hide_empty' => false));
    foreach ($terms as $term) {
        echo $term->name;
    }
}

Answer 2

You're looking to use get_terms() before 'Init' action hook.

Here's the order of the hooks run in a typical request:

muplugins_loaded
registered_taxonomy
registered_post_type
plugins_loaded
sanitize_comment_cookies
setup_theme
load_textdomain
after_setup_theme
auth_cookie_malformed
auth_cookie_valid
set_current_user
**init**
widgets_init
register_sidebar
wp_register_sidebar_widget
wp_default_scripts
wp_default_stypes
admin_bar_init
add_admin_bar_menus
wp_loaded
parse_request
send_headers
parse_query
pre_get_posts
posts_selection
wp
template_redirect
get_header
wp_head
wp_enqueue_scripts
wp_print_styles
wp_print_scripts

Answer 3

I got the same issue before, but using WP_Term_Query helped me retrieve what i needed give it a try it should work. More details here : https://developer.wordpress.org/reference/classes/WP_Term_Query/__construct/