Magento 2 Training Overriding a core class

Question

I'm trying to implement a basic m2 class override following the M2 Fundamentals Course and it is not working. Here is what I have in my Training/Test/etc/di.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © 2015 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
<preference for="Magento\Catalog\Model\Product" type="Training\Test\Model\Testproduct" />
</config>

And inside the Training\Test\Model\Testproduct.php

<?php
namespace Training\Test\Model;
class Testproduct extends \Magento\Catalog\Model\Product
{
 public function getPrice() {
 return 3;
 }
} 

I understand it's better to do plugins / events, but my question is why is the above not working?

The module is installed and I also ran the following:

php bin/magento cache:flush
rm -Rf var/cache/*
rm -Rf var/di/
rm -Rf var/generation/*
rm -Rf var/page_cache/*
php bin/magento setup:di:compile

It also shows when runnning: php bin/magento module:status

List of enabled modules:
...
Training_Test

• KAndy: Looks like your module is not installed, isn't it?
• CD Brian: It is installed. I also ran the following: php bin/magento cache:flush 993 rm -Rf var/cache/* 994 rm -Rf var/di/ 995 rm -Rf var/generation/* 996 rm -Rf var/page_cache/* 997 php bin/magento setup:di:compile
• KAndy: Can you describe how are you setup magento and add module to it?
• CD Brian: How I setup Magento? I followed the install guide and everything works fine on that front. I then followed the tutorial for building the module and ran: php -f bin/magento module:enable Training_Test I also, verified that if I change this module code to work as a plugin, it works properly. But overriding a class as above does not work.
• Max Pronko: In my view you should not override Magento classes. You may want to use Magento Plugins and extend functionality with your custom logic.

Answer 1

You can try this simple module to override \Magento\Catalog\Model\Product class. It 100% works on my local Magento 2 test environment.

Base folder: app\code

Directory tree:

└── Example
 └── OverrideModel
 ├── composer.json
 ├── etc
 │  ├── frontend
 │  │  └── di.xml
 │  └── module.xml
 ├── Model
 │  └── Product.php
 └── registration.php

File: Example/OverrideModel/composer.json

{
 "name": "example/overridemodel",
 "description": "OverrideModel module for Magento 2",
 "type": "magento2-module",
 "version": "1.0.0",
 "license": [
 "OSL-3.0",
 "AFL-3.0"
 ],
 "require": {
 "php": "~5.5.0|~5.6.0|~7.0.0",
 "magento/module-catalog": "~100.0"
 },
 "autoload": {
 "files": [
 "registration.php"
 ],
 "psr-4": {
 "Example\\OverrideModel\\": ""
 }
 }
}

File: Example/OverrideModel/registration.php

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

File: Example/OverrideModel/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="Example_OverrideModel" setup_version="1.0.0">
 <sequence>
 <module name="Magento_Catalog"/>
 </sequence>
 </module>
</config>

File: Example/OverrideModel/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">
 <preference for="Magento\Catalog\Model\Product" type="Example\OverrideModel\Model\Product" />
</config>

File: Example/OverrideModel/Model/Product.php

<?php
namespace Example\OverrideModel\Model;
class Product extends \Magento\Catalog\Model\Product {
 public function getPrice()
 {
 return 3;
 }
}

• Andrew Davie: Wish there was a 'highlight' function. Took me ages to see 'extends' rather than 'implements' and finally everything clicked.