Current Category Recent Posts

functions.php

//* Recent Posts Widget Filtered by Current Category
add_filter( 'widget_posts_args', 'my_widget_posts_args');
function my_widget_posts_args($args) {
    if ( is_category() ) { // Adds the category parameter in the query if we display a category
        $cat = get_queried_object();
        return array(
            'posts_per_page' => 10, // The number of posts shown
            'no_found_rows' => true, 
            'post_status' => 'publish', 
            'ignore_sticky_posts' => true,
            'cat' => $cat -> term_id // The current category ID
             );
    }
    else { // Keeps the normal behaviour if we are not in category context
        return $args;
    }
}