get_the_categories() but exclude children of “Uncategorized”

Question

In this function, I need to exclude any categories from $categories which are children of "Uncategorized".

function get_cats(){
    $post_cats= array();
    $categories = get_the_category();
    foreach($categories as $cat){  
        array_push($post_cats, $cat->cat_ID);
    }
    return $post_cats;
}

Thanks in advance if you can help.

Answer 1

Check if $cat->category_parent != 1 (assuming uncategorized has the default ID of 1). If your subcategories are deeper than one level you'll need to use get_ancestors to determine the top level category.

Answer 2

It should be like this,

function get_cats(){
$post_cats= array();
$categories = get_the_category();
  foreach($categories as $cat){
     if($cat->category_parent == 1 || $cat->cat_ID == 1)
     continue;
     array_push($post_cats, $cat->cat_ID);
  }
return $post_cats; }

Now the Un-categorized category and with this children filtered. You can remove this category from the admin if you need.

Check this blog

Answer 3

I believe this can help (inside foreach):

if( $cat->cat_name != 'Uncategorized' ) {
    array_push( $post_cats, $cat->cat_ID );
}

Update:

You may want to use post_is_in_descendant_category function:

if( $cat->cat_name != 'Uncategorized'
    && !post_is_in_descendant_category(
           get_term_by( 'name', 'Uncategorized', 'category' ),
           $post
        )
) {
    array_push( $post_cats, $cat->cat_ID );
}

(not tested, sorry)

Nothe, that post_is_in_descendant_category should be defined in your functions.php, please check the link.