How to add noindex,follow to Category page when sorting applied?

Question

How to add noindex,follow to category sorting pages? For example a category sort by high price or low price.

How do I add noindex,follow to this sort result.

Answer 1

You can achieve via event.

Fire an Observer on layout_load_before.

On This observer Change robot value to noindex,follow when url has query param product_list_order.

Define Observer:

Define observer at app/code/{Vendorname}/{Modulename}/etc/events.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="layout_load_before">
        <observer name="add_robot" instance="{Vendorname}\{Modulename}\Observer\NoindexfollowOnCategory" />
    </event>    
</config>

Observer Class:

<?php
/**.
 * User: Amit
 * Date: 10/29/2017
 * Time: 12:34 AM
 */

namespace {Vendorname}\{Modulename}\Observer;
use Magento\Framework\Event\ObserverInterface;

class NoindexfollowOnCategory implements ObserverInterface
{

    protected $request;

    protected $layoutFactory;

    public function __construct(
    \Magento\Framework\App\Request\Http $request,
    \Magento\Framework\View\Page\Config $layoutFactory
    ) {
        $this->request = $request;
        $this->layoutFactory = $layoutFactory;
    }



    public function execute(\Magento\Framework\Event\Observer $observer) {

    $fullActionName = $observer->getFullActionName();

     if ($fullActionName == "catalog_category_view" && $this->request->getParam('product_list_order')
        && !is_null($this->request->getParam('product_list_order'))){
          $this->layoutFactory->setRobots('NOINDEX,NOFOLLOW');
       }
    }
}