const example = 'Hello, World!';
function knowledge_cat_filter($query){
if(!is_admin() && $query->is_main_query() && is_home()){
if(isset($_GET['category'])){
$query->set('tax_query',array(
array(
'taxonomy' => 'category',
'field' => 'slug',
'terms' => $_GET['category']
)
));
}
if(isset($_GET['keyword'])){
$query->set('s',$_GET['keyword']);
}
}
}
add_action( 'pre_get_posts', 'knowledge_cat_filter' );