How to add your own products-links providers (related, upsell, crossell)

• Introduction
• Prerequisites
• Step 1: build a custom module skeleton
• Step 2: creating data patch file to insert our custom link type in Mage-OS database tables

Introduction

This tutorial defines how to add your custom product link provider. We'll go through all the needed steps and code in order to build a custom module which will provide with such functionality.

Prerequisites

Before proceeding with the below steps, please ensure you have a local installation of Mage-OS ready and running.

If you don't have it yet, please follow installation instructions in order to have Mage-OS ready for this tutorial.

Step 1: build a custom module skeleton

We'll build the module under: path-to-your-projects-root/app/code.

First step is to create our module's vendor folder and module's folder under: path-to-your-projects-root/app/code/MageOS/CustomProductLink

Where MageOS is the vendor name and CustomProductLink the name of our module.

Then we'll create the 2 mandatory files so Mage-OS recognize our module:

path-to-your-projects-root/app/code/MageOS/CustomProductLink/etc/module.xml

Where module.xml will contain basic information about our module and its modules dependencies:

<?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="MageOS_CustomProductLink" >
        <sequence>
            <module name="Magento_Catalog"/>
        </sequence>
    </module>
</config>

path-to-your-projects-root/app/code/MageOS/CustomProductLink/registration.php

Where registration.php will contain the needed code to register our module under our Mage-OS project:

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

After having this completed, we should be able to activate our module, to do so, we need to go to a console and at the Mage-OS's root directory, run:

bin/magento module:enable MageOS_CustomProductLink

and we should see an output like below:

The following modules have been enabled:
- MageOS_CustomProductLink

This means that our new module has been correctly registered and enabled in our project.

Step 2: creating data patch file to insert our custom link type in Mage-OS database tables

Before proceeding with this step, it's recommended checking your current database (especially if it's not a clean Mage-OS installation) to see what was the latest product link type inserted in order to reserve a new ID for our new custom link type.

To do so, connect to your database, navigate to table catalog_product_link_type and check for the highest link_type_id value.

In a fresh Mage-OS installation, there should be something like that:

> select * from catalog_product_link_type;
+--------------+------------+
| link_type_id | code       |
+--------------+------------+
|            1 | relation   |
|            3 | super      |
|            4 | up_sell    |
|            5 | cross_sell |
+--------------+------------+

As we can see, the highest link_type_id is 5, so we'll use 6 for our custom type.

Now, we're ready to create our data patch file. To do so, we need to create a data patch file under: path-to-your-projects-root/app/code/MageOS/CustomProductLink/Setup/Patch/Data/AddCustomProductLink.php

This file will insert the needed data to link tables so our custom product link type will be recognized by Mage-OS.

The file looks like below:

<?php
 
declare(strict_types=1);
 
namespace MageOS\CustomProductLink\Setup\Patch\Data;
 
use Magento\Framework\Setup\ModuleDataSetupInterface;
use Magento\Framework\Setup\Patch\DataPatchInterface;
 
class AddCustomProductLink implements DataPatchInterface
{
    private ModuleDataSetupInterface $moduleDataSetup;
 
    public function __construct(ModuleDataSetupInterface $moduleDataSetup)
    {
        $this->moduleDataSetup = $moduleDataSetup;
    }
 
    public static function getDependencies()
    {
        return [];
    }
 
    public function getAliases()
    {
        return [];
    }
 
    public function apply()
    {
        $this->moduleDataSetup->getConnection()->insertForce(
            $this->moduleDataSetup->getTable('catalog_product_link_type'),
            [
                'link_type_id' => 6,
                'code' => 'custom'
            ]
        );
 
        $this->moduleDataSetup->getConnection()->insertMultiple(
            $this->moduleDataSetup->getTable('catalog_product_link_attribute'),
            [
                [
                    'link_type_id' => 6,
                    'product_link_attribute_code' => 'position',
                    'data_type' => 'int'
                ]
            ]
        );
    }
}

After having this done, we should run:

bin/magento setup:upgrade

And if everything went well, we should see an output like below:

> select * from catalog_product_link_type;
+--------------+------------+
| link_type_id | code       |
+--------------+------------+
|            1 | relation   |
|            3 | super      |
|            4 | up_sell    |
|            5 | cross_sell |
|            6 | custom     |
+--------------+------------+

Like explained above, we're using 6 for our link_type_id.

Also, you can add some attributes to the custom link type, we'll use position and short_description so you can see we can use different attribute types.

For now, 3 data types are allowed for these attributes, as there are 3 tables reserved for attribute types in the database: catalog_product_link_attribute_decimal, catalog_product_link_attribute_varchar, catalog_product_link_attribute_int.