Having Trouble With get_category_by_slug In a Custom Function

Question

Here's my custom function to list child categories by the parent slug.

function ribbon_list_cats($parent_cat_slug)
{
    $parent_category = get_category_by_slug($parent_cat_slug);
    if ($parent_category->count != 0) {
        echo "<ul>";
        echo wp_list_categories('title_li=&child_of='.$parent_category->term_id.'&hide_empty=0&show_option_none=&echo=0');
        echo "</ul>";
    }
}

I'm having trouble getting it to return and output. It doesn't throw an error. I'm using it multiple times so I created this but when I do it like so:

$parent_category = get_category_by_slug('lifestyle');
if ($parent_category->count != 0) {
    echo "<ul>";
    echo wp_list_categories('title_li=&child_of='.$parent_category->term_id.'&hide_empty=0&show_option_none=&echo=0');
    echo "</ul>";
}

right in the template it works fine. But that's a lot of code to repeat over and over again.

Hope that makes sense. Thanks!

Answer 1

function ribbon_list_cats( $parent_cat_slug, $echo = true )
{
    $parent_category = get_category_by_slug( $parent_cat_slug );
    if ( $parent_category->count > 0 ) 
    {
        $output  = '<ul>';
        $output .= wp_list_categories('title_li=&child_of='.$parent_category->term_id.'&hide_empty=0&show_option_none=&echo=0');
        $output .= '</ul>';
    }
    // Debug: uncomment the following line
    // echo '<pre>'; var_dump( $output ); echo '</pre>';

    if ( $echo === false )
        return $output;

    return print $output;
}

// Call it like this:
ribbon_list_cats( 'uncategorized' );