How to spell canonical?

Question

PHP

It is necessary that canonical be displayed only on the main page. Did it like this:

$currentUrl = "https://" . $_SERVER['SERVER_NAME']; 
if($currentUrl == "https://www.my-shop.com") {
  $APPLICATION->AddHeadString('<link rel="canonical" href="https://www.my-shop.com/" />');
}

As expected, canonical also appears on ...my-shop.com/cars, and on ...my-shop.com/bikes, and so on.

Answer 1

Did it like this:

$val = $APPLICATION->GetCurPageParam("", array_keys($_GET), false); 
$APPLICATION->SetPageProperty("canonical", $val);

Answer 2

You need a REQUEST_URI or use your app's router