How to create custom product attribute using Data Patch in Magento 2

Oct 31, 2024 5 min read

Magento 2 provides the provision to create custom product attribute programmatically.

We can create custom product attributes using the InstallData setup script as well as using Data Patch. After the release of Magento version 2.3, a data patch is a standard approach to managing database modifications. Using data patch we don’t need to manage setup_version in etc/module.xml. So in this blog, we cover the concept of creating custom product attributes using Data Patch with full code. In the following example, we are creating dropdown attribute

A data patch is a class that contains data modification instructions. It is defined in a Vendor/Module_Name/Setup/Patch/Data/Patch_Name.php file and implements \Magento\Framework\Setup\Patch\DataPatchInterface.

1: Register Module

registration.php app/code/SMG/CustomProductAttribute/registration.php

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

module.xml app/code/SMG/CustomProductAttribute/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="SMG_CustomProductAttribute">
        <sequence>
            <module name="Magento_Eav"/>
        </sequence>
    </module>
</config>

2: Data Patch

File - app/code/SMG/CustomProductAttribute/Setup/Patch/Data/AddDropdownProductAttribute.php

<?php

declare(strict_types=1);

namespace SMG\CustomProductAttribute\Setup\Patch\Data;

use Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface;
use Magento\Eav\Setup\EavSetup;
use Magento\Eav\Setup\EavSetupFactory;
use Magento\Framework\Setup\ModuleDataSetupInterface;
use Magento\Framework\Setup\Patch\DataPatchInterface;
use Magento\Catalog\Model\Product;
use Magento\Catalog\Model\Product\Type;
use Psr\Log\LoggerInterface;

class AddDropdownProductAttribute implements DataPatchInterface
{
    /**
     * @var ModuleDataSetupInterface
     */
    private ModuleDataSetupInterface $moduleDataSetup;

    /**
     * @var EavSetupFactory
     */
    private EavSetupFactory $eavSetupFactory;

    /**
     * @var LoggerInterface
     */
    private LoggerInterface $logger;

    /**
     * @param ModuleDataSetupInterface $moduleDataSetup
     * @param EavSetupFactory $eavSetupFactory
     * @param LoggerInterface $logger
     */
    public function __construct(
        ModuleDataSetupInterface $moduleDataSetup,
        EavSetupFactory $eavSetupFactory,
        LoggerInterface $logger
    ) {
        $this->moduleDataSetup = $moduleDataSetup;
        $this->eavSetupFactory = $eavSetupFactory;
        $this->logger = $logger;
    }

    /**
     * @return void
     */
    public function apply()
    {
        try {
            $productTypes = implode(',', [Type::TYPE_SIMPLE, Type::TYPE_VIRTUAL]);

            /** @var EavSetup $eavSetup */
            $eavSetup = $this->eavSetupFactory->create(['setup' => $this->moduleDataSetup]);

            $eavSetup->addAttribute(Product::ENTITY, 'sample_dropdown_attribute', [
                'type' => 'int',
                'backend' => \SMG\CustomProductAttribute\Model\Entity\Attribute\Backend\TestBackend::class,
                'frontend' => \SMG\CustomProductAttribute\Model\Entity\Attribute\Frontend\TestFrontend::class,
                'label' => 'Sample Dropdown Attribute',
                'input' => 'select',
                'class' => '',
                'source' => \SMG\CustomProductAttribute\Model\Source\Config\Options::class,
                'global' => ScopedAttributeInterface::SCOPE_GLOBAL,
                'visible' => true,
                'required' => false,
                'user_defined' => false,
                'default' => '0',
                'searchable' => false,
                'filterable' => false,
                'comparable' => false,
                'visible_on_front' => true,
                'used_in_product_listing' => true,
                'unique' => false,
                'apply_to' => $productTypes
            ]);

        } catch (\Exception $e) {
            $this->logger->critical($e);
        }
    }

    /**
     * @return array
     */
    public static function getDependencies(): array
    {
        return [];
    }

    /**
     * @return array
     */
    public function getAliases(): array
    {
        return [];
    }
}

For creating multiselect type product attribute, we just need to change the input value to multiselect insted of select in the above sample code.

3: Source model

To populate dropdown options, we need to define a custom source model. The main purpose of a source model is to provide options for select-type attributes (select and multiselect). A source model must implement Magento\Eav\Model\Entity\Attribute\Source\SourceInterface or extend Magento\Eav\Model\Entity\Attribute\Source\AbstractSource.

File - app/code/SMG/CustomProductAttribute/Model/Source/Config/Options.php

<?php
declare(strict_types=1);
namespace SMG\CustomProductAttribute\Model\Source\Config;
use Magento\Eav\Model\Entity\Attribute\Source\AbstractSource;
class Options extends AbstractSource
{
    public function getAllOptions(): array
    {
        $this->_options = [
            ['label' => '', 'value' => '0'],
            ['label' => 'Small', 'value' => '1'],
            ['label' => 'Medium', 'value' => '2'],
            ['label' => 'Large', 'value' => '3'],
            ['label' => 'Test', 'value' => '4'],

        ];
        return $this->_options;
    }
}

product view page

4: Frontend model

The value of the attribute's frontend_model property must be set to a class that implements Magento\Eav\Model\Entity\Attribute\Frontend\FrontendInterface(or extends Magento\Eav\Model\Entity\Attribute\Frontend\AbstractFrontend , which is more meaningful). The key method to implement is getValue() which takes an entity model as a parameter.

file - app/code/SMG/CustomProductAttribute/Model/Entity/Attribute/Frontend/TestFrontend.php

<?php
declare(strict_types=1);
namespace SMG\CustomProductAttribute\Model\Entity\Attribute\Frontend;

use Magento\Eav\Model\Entity\Attribute\Frontend\AbstractFrontend;
use Magento\Framework\DataObject;
/**
 * Frontend model class inherited from AbstractFrontend
 */
class TestFrontend extends AbstractFrontend
{
    /**
     * override getValue method and set frontend_model
     *
     * @param \Magento\Framework\DataObject $object
     * @return void
     */
    public function getValue(\Magento\Framework\DataObject $object)
    {
        $attribute_code = $this->getAttribute()->getAttributeCode();
        $value = $object->getData($attribute_code);

        if($value) {
            $valueOption = $this->getOption($value); 
            return nl2br(htmlspecialchars($valueOption));
        }
    } 
}

The main purpose of the frontend model is to render an attribute on the storefront, on the product view page:

product view page

5: Backend model

Backend model must implement Magento\Eav\Model\Entity\Attribute\Backend\BackendInterface or extend Magento\Eav\Model\Entity\Attribute\Backend\AbstractBackend

Backend modules are created with a purpose to upload / save / delete / validate attribute values.

Example of attribute value validation:

<?php
declare(strict_types=1);
namespace SMG\CustomProductAttribute\Model\Entity\Attribute\Backend;

use Magento\Eav\Model\Entity\Attribute\Backend\AbstractBackend;
use Magento\Framework\DataObject;
/**
 * Backend model class inherited from AbstractBackend
 */
class TestBackend extends AbstractBackend
{
    /**
     * Validate object
     *
     * @param \Magento\Framework\DataObject $object
     * @return bool
     * @throws LocalizedException
     * @SuppressWarnings(PHPMD.CyclomaticComplexity)
     */
    public function validate($object)
    {
    	$attribute_code = $this->getAttribute()->getAttributeCode();
        $value = $object->getData($attribute_code);

        if ($value == 4) {
            $valueOption = $this->getOption($value);
        	throw new \Magento\Framework\Exception\LocalizedException(__("Can't set value %1", $valueOption));
        }
        return true;
    }

    public function getOption($optionId)
    {
        $source = $this->getAttribute()->getSource();
        if ($source) {
            return $source->getOptionText($optionId);
        }
        return false;
    }
}

Then run the following command:

bin/magento setup:upgrade

Supravat Mondal

Supravat Mondal