Custom Content Attribute

/* Custom Content Attribute */
function change_content_attr( $attr, $name, $term_id ) {
    /* For Category */
    if ( 'jnews_category_' === $name ) {
        $attr['sort_by'] = 'popular_post';
    }
    return $attr;
}
add_filter( 'jnews_get_content_attr', 'change_content_attr', 10, 3 );