danharper

Thank-you Michael.

Michael, in your example, you are creating a function in functions.php which calls get_categories(), but you use that function in a front-end file.

Our problem is that get_categories() does not work when used solely in the back-end – ie. we’re creating a options page for our theme which requires a list of the categories.

Try out my example, and you’ll see it does not work.

This is definitely either an undocumented feature change or a bug in WP 2.8 as the get_categories() function can not retrieve any categories when used inside functions.php – anywhere on the front-end is fine.

To test this, include the following code to the very top of a functions.php file:

echo '<pre>';
print_r(get_categories('hide_empty=0'));
echo '</pre>';

Now, as you know, this should print out an array containing all categories on the site.
Try this on 2.7.1 and all other older versions, the code works correctly by printing out:

Array
(
    [0] => stdClass Object
        (
            [term_id] => 3
            [name] => Tutorials
            [slug] => tutorials
            [term_group] => 0
            [term_taxonomy_id] => 3
            [taxonomy] => category
            [description] =>
            [parent] => 0
            [count] => 5
            [cat_ID] => 3
            [category_count] => 5
            [category_description] =>
            [cat_name] => Tutorials
            [category_nicename] => tutorials
            [category_parent] => 0
        )
....
....
)

However in 2.8, the following is output:

Array
(
    [errors] => Array
        (
            [invalid_taxonomy] => Array
                (
                    [0] => Invalid Taxonomy
                )

        )

    [error_data] => Array
        (
        )

)

As I stated, the code works fine in front-end files, but not in the back-end.

This is not a problem with a theme or plugin error, as exactly the same problem is seen if you add the code to the default WordPress themes.