How can I add a filter for specific categories on functions.php? - wordpress

Question

I am on functions.php and I want to add this filter:
function graphene_alter_the_query( $request ) {
$dummy_query = new WP_Query();
$dummy_query->parse_query( $request );
if (!is_category('25')) {
$request['gdsr_sort'] = 'rating';
}
else {
$request['gdsr_sort'] = 'comment_count';
}
return $request;
}
add_filter( 'request', 'graphene_alter_the_query' );
the filter should do the same thing for all categories except cat 25 but seems like it cant tell it apart like if the IF condition is not detecting the category so I tried to debug it by looking at the values in WP_Query and I get this:
$myquery = new WP_Query(); print_r($myquery);
WP_Query Object ( [query] => Array ( [category_name] => 'my cat' ) [query_vars] => Array ( [category_name] => 'my cat' [error] => [m] => [p] => 0 [post_parent] => [subpost] => [subpost_id] => [attachment] => [attachment_id] => 0 [name] => [pagename] => [page_id] => 0 [second] => [minute] => [hour] => [day] => 0 [monthnum] => 0 [year] => 0 [w] => 0 [tag] => [cat] => [tag_id] => [author] => [author_name] => [feed] => [tb] => [paged] => 0 [meta_key] => [meta_value] => [preview] => [s] => [sentence] => [title] => [fields] => [menu_order] => [embed] => [category__in] => Array ( ) [category__not_in] => Array ( ) [category__and] => Array ( ) [post__in] => Array ( ) [post__not_in] => Array ( ) [post_name__in] => Array ( ) [tag__in] => Array ( ) [tag__not_in] => Array ( ) [tag__and] => Array ( ) [tag_slug__in] => Array ( ) [tag_slug__and] => Array ( ) [post_parent__in] => Array ( ) [post_parent__not_in] => Array ( ) [author__in] => Array ( ) [author__not_in] => Array ( ) ) [tax_query] => WP_Tax_Query Object ( [queries] => Array ( [0] => Array ( [taxonomy] => category [terms] => Array ( [0] => 'my cat' ) [field] => slug [operator] => IN [include_children] => 1 ) ) [relation] => AND [table_aliases:protected] => Array ( ) [queried_terms] => Array ( [category] => Array ( [terms] => Array ( [0] => 'my cat' ) [field] => slug ) ) [primary_table] => [primary_id_column] => ) [meta_query] => [date_query] => [post_count] => 0 [current_post] => -1 [in_the_loop] => [comment_count] => 0 [current_comment] => -1 [found_posts] => 0 [max_num_pages] => 0 [max_num_comment_pages] => 0 [is_single] => [is_preview] => [is_page] => [is_archive] => 1 [is_date] => [is_year] => [is_month] => [is_day] => [is_time] => [is_author] => [is_category] => 1 [is_tag] => [is_tax] => [is_search] => [is_feed] => [is_comment_feed] => [is_trackback] => [is_home] => [is_privacy_policy] => [is_404] => [is_embed] => [is_paged] => [is_admin] => [is_attachment] => [is_singular] => [is_robots] => [is_favicon] => [is_posts_page] => [is_post_type_archive] => [query_vars_hash:WP_Query:private] => 6d85cdf18f3e6a58a470a3002d5807fc [query_vars_changed:WP_Query:private] => [thumbnails_cached] => [stopwords:WP_Query:private] => [compat_fields:WP_Query:private] => Array ( [0] => query_vars_hash [1] => query_vars_changed ) [compat_methods:WP_Query:private] => Array ( [0] => init_query_flags [1] =>
but both tag_id and cat appear empty. Why is that?