How to limit number of number of categories displayed by categories widget

You could show the Category widgets as a dropdown instead, if you have large number of categories.

I’m not sure how useful it is to limit categories when ordered by name.

You might try to order by count to display the most used categories:

add_filter( 'widget_categories_args', function( $args )
{
    $args['number']         = 1;
    $args['orderby']        = 'count';
    $args['order']          = 'DESC';
    $args['hierarchical']   = 0;
    $args['hide_empty']     = 1;

    return $args;
} );

but there are other options like include and exclude.

Note that the Category widget uses wp_list_categories() that uses get_categories(), that’s a wrapper for get_terms() that uses a WP_Term_Query object that contains the following part, in the WP_Term_Query::get_terms() class method:

  // Don't limit the query results when we have to descend the family tree.
  if ( $number && ! $hierarchical && ! $child_of && '' === $parent ) {
        if ( $offset ) {
            $limits="LIMIT " . $offset . ',' . $number;
         } else {
             $limits="LIMIT " . $number;
         }
  } else {
      $limits="";
  }

The dropdown option uses wp_dropdown_categories().

Related Posts: