How I can override this Magento\Catalog\Block\Breadcrumbs.php

Question

How I can override the breadcrumb.php file .as If I am using in app/design/frontend/Oc/jb/Magento_Catalog/Block/Breadcrumb.php its giving error.

UPDATED CODE

 // @codingStandardsIgnoreFile
/**
 * Catalog breadcrumbs
 */
namespace Oc\Jb\Block;
use Magento\Catalog\Helper\Data;
use Magento\Framework\View\Element\Template\Context;
class MyBreadcrumbs extends \Magento\Catalog\Block\Breadcrumbs
{
 public function __construct()
 {
 Data $catalogData
 Context $context;
 $data = array();
 parent::__construct($context,$catalogData, $data);
 }
 public function getTitleSeparator($store = null)
 {
 $separator = (string)$this->_scopeConfig->getValue('catalog/seo/title_separator', \Magento\Store\Model\ScopeInterface::SCOPE_STORE, $store);
 return ' ' . $separator . ' ';
 }
 public function getCategory ($product) { 
 $_categoryFactory = $this->_objectManager->create('Magento\Catalog\Model\CategoryFactory');
 // for multiple categories, select only the first one
 // remember, index = 0 is 'Default' category
 if (! $product->getCategoryIds())
 return null;
 if (isset ( $product->getCategoryIds()[1]))
 $categoryId = $product->getCategoryIds()[1] ;
 else
 $categoryId = $product->getCategoryIds()[0] ;
 // Additionally for other types of attributes (select, multiselect, ..)
 $category = $_categoryFactory->create()->load($categoryId);
 return ['label' => $category->getName(), 'url' => $category->getUrl() ] ;
 }
 /**
 * Preparing layout
 *
 * @return \Magento\Catalog\Block\Breadcrumbs
 */
 protected function _prepareLayout()
 {
 $product = $this->_coreRegistry->registry('current_product'); 
 //return parent::_prepareLayout();
 if ($breadcrumbsBlock = $this->getLayout()->getBlock('breadcrumbs')) {
 $breadcrumbsBlock->addCrumb(
 'home',
 [
 'label' => __('Home'),
 'title' => __('Go to Home Page'),
 'link' => $this->_storeManager->getStore()->getBaseUrl()
 ]
 );
 $title = [];
 $path = $this->_catalogData->getBreadcrumbPath();
 // If we are at the product page and the $path does not include a category, 
 // then we will append the category link here manually
 // Magento doesn't seem to append category paths to breadcrums consistently
 // Reported here; https://github.com/magento/magento2/issues/7967
 if($product != null ) {
 // check for category path
 $foundCatPath=false;
 foreach ($path as $name => $breadcrumb) {
 if ( strpos ( $name, 'category' ) > -1 ) 
 $foundCatPath=true;
 }
 // append the category path
 if (! $foundCatPath) {
 $productCategory = $this->getCategory($product) ;
 if ($productCategory) {
 $categoryPath = [ 'category' => ['label' => $productCategory['label'] , 'link' => $productCategory['url']] ];
 $path = array_merge ($categoryPath ,$path );
 } 
 }
 }
 foreach ($path as $name => $breadcrumb) {
 $breadcrumbsBlock->addCrumb($name, $breadcrumb);
 $title[] = $breadcrumb['label'];
 }
 // print_r ($path );
 // die ();
 $this->pageConfig->getTitle()->set(join($this->getTitleSeparator(), array_reverse($title)));
 }
 return parent::_prepareLayout();
 }
}
}

Answer 1

You can also use a plugin/interceptor, which is architecturally a more streamline solution than others posted. You can accomplish this with either the "before" or "around" methods. Each has it's benefits.

registration.php

<?php
\Magento\Framework\Component\ComponentRegistrar::register(
 \Magento\Framework\Component\ComponentRegistrar::MODULE,
 'Foo_Bar',
 __DIR__
);

module.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
 <module name="Foo_Bar" setup_version="0.0.1" />
</config>

di.xml

<?xml version="1.0"?>
<config>
 <type name="Magento\Theme\Block\Html\Breadcrumbs">
 <plugin name="foo_bar_plugin_breadcrumbs_modification" type="Foo\Bar\Plugin\BreadcrumbsPlugin" sortOrder="1" />
 </type>
</config>

BreadcrumbsPlugin.php

<?php
namespace Foo\Bar\Plugin;
use \Magento\Theme\Block\Html\Breadcrumbs;
class BreadcrumbsPlugin
{
 // This is probably the "correct" way to account for this scenario
 public function beforeAddCrumb(Breadcrumbs $breadcrumbs, $crumbName, $crumbInfo)
 {
 if (isset($crumbInfo['label'])) {
 // This is where you can modify the breadcrumb text
 $crumbInfo['label'] = __($crumbInfo['label'] . ' baz');
 }
 return [
 $crumbName,
 $crumbInfo,
 ];
 }
 // Alternatively, you can use the "around" method
 public function aroundAddCrumb(Breadcrumbs $breadcrumbs, callable $proceed, $crumbName, $crumbInfo)
 {
 if (isset($crumbInfo['label'])) {
 // This is where you can modify the breadcrumb text
 $crumbInfo['label'] = __($crumbInfo['label'] . ' baz');
 }
 $proceed($crumbName, $crumbInfo);
 }
}

Answer 2

You must create a module first.

1. Module creation. Create file app/code/Oc/Jb/etc/module.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
 <module name="Oc_Jb" setup_version="1.0.0">
 </module>
</config>

and app/code/Oc/Jb/registration.php

<?php
\Magento\Framework\Component\ComponentRegistrar::register(
 \Magento\Framework\Component\ComponentRegistrar::MODULE,
 'Oc_Jb',
 __DIR__
);

2. Overriding Block Create file app/code/Oc/Jb/etc/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">
<preference for="Magento\Catalog\Block\Breadcrumbs.php
" type="Oc\Jb\Block\MyBreadcrumbs.php" />
</config>

Create your block file Oc/Jb/Block/MyBreadcrumbs.php. During overriding you must take care of what the parent class's constructor needs. In your case for Magento\Catalog\Block\Breadcrumbs, you will have to provide Context $context, Data $catalogData, array $data = []. For reference check core file.

// @codingStandardsIgnoreFile
/**
 * Catalog breadcrumbs
 */
namespace Oc\Jb\Block;
use Magento\Catalog\Helper\Data;
use Magento\Framework\View\Element\Template\Context;
class MyBreadcrumbs extends \Magento\Catalog\Block\Breadcrumbs
{
 public function __construct()
 {
 Data $catalogData
 Context $context;
 $data = array();
 parent::__construct($context,$catalogData, $data);
 }
 //make necessary changes here.
}

3. Run following commands:

php bin/magento module:enable Oc_Jb
php bin/magento setup:upgrade
php bin/magento setup:di:compile
php bin/magento setup:static-content:deploy
php bin/magento cache:clean
php bin/magento cache:flush

• Learner: thanks for replying. I need to write all code in __constuct () ? As I want to update that code gist.github.com/mbahar/82703c4b95d924d9bc8e6990202fdeba
• Purushotam Sangroula: Please check my updated answer.
• Learner: all step successfully done but still vendor is calling
• Learner: I updated breadcrumb.php code which I am using now
• Purushotam Sangroula: tere is another way as well. I will post it tomorrow. I'm sleeping now.

Answer 3

You can't override php classes using theme. Just create magento module and override class using preferences : tutorial is here

• Learner: I want this file to replace breadcrumbs.php gist.github.com/mbahar/82703c4b95d924d9bc8e6990202fdeba
• Stepan Furman: Breadcrumbs.php is php class you cant override it like phtml files. Follow my instruction and you'll get success.
• Learner: I am confuse in steps . Like what will be my namespace Inchoo\Helloworld\Controller\Index; And what will that path mean ? use Magento\Framework\App\Action\Context; . Can you share some steps if possible ?
• Stepan Furman: First read this article inchoo.net/magento-2/how-to-create-a-basic-module-in-magento-2
• Stepan Furman: @Learner namespace is the same as theme namespace in your case Oc/Jb or another you want. Mostly used vendorname/modulepurpose. For example Google/ReCaptcha. Then create folders like Oc/Jb/Block/Catalog/Block/Breadcrumbs.php and di.xml like in tutorial in second link