List all taxonomies assigned from a custom post type

Question

I am really desperate for help here, been trying do this since yesterday and still no luck, so here is what I want to achieve

Collection = custom post type

• Material = custom taxonomy assigned to "collection"

  • Mat1 = term
  • Mat2 = term

• Body = custom taxonomy assigned to "collection"

  • Body1 = term
  • Body2 = term

• Color = custom taxonomy assigned to "collection"

  • Color1 = term
  • Color2 = term

The structure will be something like this

- Material
  - Mat1
  - Mat2
- Body
  - Body1
  - Body2
- Color
  - Color1
  - Color2

I got this code but it's not working at all

$post_type = 'collection';
$taxonomies = get_object_taxonomies( (object) array( 'post_type' => $post_type, 'hide_empty' => true ) );

foreach( $taxonomies as $taxonomy ){
    echo $taxonomy->name;

    $terms = get_terms( $taxonomy );
    foreach( $terms as $term ){
        echo '<li>';
        echo $term->name;
        echo '</li>';
    }
}

Answer 1

If you look at the documentation for get_object_taxonomies() you'll notice a few things, namely that for your purposes you'll want to pass the name of a post type as the first argument, and get the objects with the second. It also appears you're conflating the arguments for both get_object_taxonomies() and get_terms().

Also with the get_terms() function, if you're using WP 4.5 or higher, you'll want to pass the taxonomy in the $args array.

$taxonomies = get_object_taxonomies( 'collection', 'objects' );

foreach( $taxonomies as $taxonomy ){
    echo $taxonomy->name;

    $terms = get_terms(array(
        'taxonomy' => $taxonomy->name,
        'hide_empty' => false,
    ));

    foreach( $terms as $term ){
        echo "<li>{$term->name}</li>";
    }
}