How to remove an automatically generated canonical link from a product page using custom layout XML?

Question

I already have canonical links turned on in my CE 1.9 install, but if I didn't I know that I can add a canonical link to a product using custom layout XML this way:

<reference name="head">
<action method="addLinkRel">
<rel>canonical</rel>
<href>https://www.example.html</href>
</action>
</reference>

I would like, however, to customize a particular product's canonical link and I would like to use custom XML to remove the original one before I add in the next so I don't have two links. Is this possible without modifying code?

Answer 1

According to /app/code/core/Mage/Page/Block/Html/Head.php method addLinkRel:

     public function addLinkRel($rel, $href)
     {
        $this->addItem('link_rel', $href, 'rel="' . $rel . '"');
        return $this;
     }

it operating with addItem method, which operates with $this->_data['items'] so you can basically use same way removeItem method in your xml :

    <action method="removeItem"><type>link_rel</type><href>https://www.example.html</href></action>

Answer 2

I have been trying to figure this out for quite a while now and none of the solutions I found worked. All I had to do to get it to work was to add another removeItem action with the same link but with ?___SID=U added to the end.

The only reason I can think that this works is that the removeItem action is looking for the URL before the URL rewrite kicks in. Don't quote me on that though :)

<reference name="head">
   <action method="removeItem"><type>link_rel</type><href>{LINK}</href></action>
   <action method="removeItem"><type>link_rel</type><href>{LINK}?___SID=U</href></action>
   <action method="addLinkRel"><rel>canonical</rel><href>{LINK}</href></action>
</reference>