Remove meta box except on category pages

Question

To disable custom fields except on category pages, how would I check if it's a category page?

Maybe it would be like this:

add_action( 'admin_menu', 'remove_custom_fields' );

function remove_custom_fields() {
    if(  /* code to check if page is not category page */){

        remove_meta_box('postcustom', 'page', 'normal');

    }

But I don't know how to do the check - I tried with

$screen = get_current_screen();
if($screen->taxonomy != 'category') { //etc}

but that didn't seem to work in the admin_menu action, but I could use it with the current_screen action, but that's the wrong place to remove the custom fields I guess.

---- EDIT ----

I realized that the category pages does not seem to have custom fields available , so it won't actually matter if I exclude the category pages from the removing of custom fields.

Answer 1

You Can use ACF Plugin to add a custom fields just for categories.

Add a new Field Group and set location to any of two settings: