Ttdfjt

turncate Meta title and meta description on pdp page how we can do that in which file we need to make changes .

In PDP, meta title and description is set via the product view helper class: MagentoCatalogHelperProductView::preparePageMetadata().

So what you need to do is write a preference for this helper class as the method preparePageMetadata() is a private method. But, the best option would be doing the same through a plugin. To do this, you need to write an around plugin for the method MagentoCatalogHelperProductView:: prepareAndRender() which is what actually call the private method preparePageMetadata().

So I will just show you how you can achieve this through a plugin.

File: app/code/[Namespace]/[Module]/etc/frontend/di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
 <type name="MagentoCatalogHelperProductView">
 <plugin
 name="NamespaceModuleAlterPDPMetaTags"
 type="NamespaceModulePluginCatalogHelperProductViewPlugin" />
 </type>
</config>

Basically, this file will register our plugin dependency inside our module Namespace_Module.

File: app/code/[Namespace]/[Module]/Plugin/Catalog/Helper/Product/ViewPlugin.php

<?php

namespace NamespaceModulePluginCatalogHelperProduct;

use MagentoCatalogHelperProductView as ProductViewHelper;
use MagentoFrameworkRegistry;
use MagentoFrameworkViewResultPage;
use MagentoFrameworkStdlibStringUtils;


class ViewPlugin

 /**
 * @var MagentoFrameworkRegistry $coreRegistry,
 */
 private $coreRegistry;

 private $resultPage;

 private $string;

 public function __construct(Registry $coreRegistry, StringUtils $string)
 
 $this->coreRegistry = $coreRegistry;
 $this->string = $string;
 

 public function aroundPrepareAndRender(
 ProductViewHelper $productViewHelper,
 callable $proceed,
 Page $resultPage,
 $productId,
 $controller,
 $params = null
 ) 
 // collecting result page instance for future use
 $this->resultPage = $resultPage;

 // send the control to the original method
 $result = $proceed($resultPage, $productId, $controller, $params);

 // after meta title and description is generated, this will be executed

 // make sure the helper instance is correct
 if (!$result instanceof ProductViewHelper) 
 return $productViewHelper;
 

 // collecting product information from the core registry
 $product = $this->coreRegistry->registry('product');

 // changing meta title and description as needed
 $this->alterMetaTitle($product);
 $this->alterMetaDescription($product);

 return $result;
 

 /**
 * Changing meta title of PDP; Allowing only 60 characters
 * @param $product
 */
 private function alterMetaTitle($product)
 
 $pageConfig = $this->resultPage->getConfig();
 $title = $product->getMetaTitle();

 if ($title) 
 $pageConfig->getTitle()->set($this->string->substr($title, 0, 60));
 
 

 /**
 * Changing meta description of PDP; Allowing only 60 characters
 * @param $product
 */
 private function alterMetaDescription($product)
 
 $pageConfig = $this->resultPage->getConfig();
 $description = $product->getMetaDescription();

 if ($description) 
 $pageConfig->setDescription($this->string->substr($description, 0, 60));
 else 
 $pageConfig->setDescription($this->string->substr($product->getDescription(), 0, 60));
 
 

As you can see, we wrote an around plugin for the method prepareAndRender(). Why we are relying on an around plugin is because we need the parameter $resultPage of the method in order to alter the meta title and description. Also, we need $product instance in order to retrieve the meta title and description. Product initialization is also happening inside prepareAndRender() method and hence will be obtained through the registry.

You can customize the methods alterMetaTitle() and alterMetaDescription() as per your need. Currently, it will enforce 60 character limit to both meta title and description.

I hope that gives you an idea.

Note: Module creation and usage of the plugin is out of scope concepts as per this question. If you need to know more details, please refer devdocs.