Adding Custom Attributes to Sales Order Item

Oct 13, 2025 by wbrum.org 65 views

Introduction

In the world of e-commerce, having a robust and customizable API is crucial for seamless integration with third-party services. Magento 2 provides a powerful REST API that allows developers to interact with the platform's data. However, by default, the sales order item API response does not include custom attributes. In this article, we will explore how to add a custom "sales_order_item" attribute to the API response.

Adding Custom Attributes to Sales Order Item

Before we dive into customizing the API response, let's review how to add custom attributes to the sales order item throughout the order process. We followed the official Magento 2 guide to add a custom product attribute to the quote and sales order item. This involved creating a new attribute in the admin panel, adding it to the sales order item table, and updating the relevant modules to include the new attribute.

Custom Attribute Added to Sales Order Item Table

Our custom attribute is successfully added to the sales_order_item table. However, when we retrieve the sales order item data through the API, the custom attribute is not included in the response. This is where we need to customize the API response to include our custom attribute.

Customizing the API Response

To customize the API response, we need to create a new module that will extend the existing sales order item API. We will create a new module called CustomSalesOrderItemApi that will override the existing sales_order_item resource model.

Step 1: Create a new module

Create a new directory CustomSalesOrderItemApi in the app/code directory. Inside this directory, create the following files:

registration.php
etc/module.xml
etc/di.xml
Model/ResourceModel/Sales/Order/Item.php

Step 2: Register the module

In the registration.php file, add the following code:

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

Step 3: Define the module configuration

In the etc/module.xml file, add the following code:

<?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="CustomSalesOrderItemApi" setup_version="1.0.0"/>
</config>

Step 4: Define the dependency injection configuration

In the etc/di.xml file, add the following code:

<?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\Sales\Api\Data\OrderItemInterface" type="CustomSalesOrderItemApi\Model\ResourceModel\Sales\Order\Item"/>
</config>

Step 5: Create the custom resource model

In the Model/ResourceModel/Sales/Order/Item.php file, add the following code:

namespace CustomSalesOrderItemApi\Model\ResourceModel\Sales\Order; Q: What is the purpose of customizing the sales order item API response? A: The purpose of customizing the sales order item API response is to include custom attributes in the API response. This allows developers to retrieve the custom attributes along with the standard sales order item data. Q: How do I add a custom attribute to the sales order item table? A: To add a custom attribute to the sales order item table, you need to create a new attribute in the admin panel and add it to the sales order item table. You can follow the official Magento 2 guide to add a custom product attribute to the quote and sales order item. Q: What is the difference between the sales_order_item resource model and the custom resource model? A: The sales_order_item resource model is the default resource model provided by Magento 2, while the custom resource model is a new resource model created to override the default resource model. The custom resource model is used to include custom attributes in the API response. Q: How do I create a new module to customize the sales order item API response? A: To create a new module to customize the sales order item API response, you need to create a new directory in the app/code directory and add the necessary files, including the registration.php, etc/module.xml, and etc/di.xml files. Q: What is the purpose of the etc/di.xml file? A: The etc/di.xml file is used to define the dependency injection configuration for the custom resource model. It specifies the preference for the Magento\Sales\Api\Data\OrderItemInterface interface, which is used to include custom attributes in the API response. Q: How do I include custom attributes in the API response? A: To include custom attributes in the API response, you need to add the custom attributes to the sales_order_item resource model using the etc/di.xml file. You can then retrieve the custom attributes along with the standard sales order item data using the API. Q: What are the benefits of customizing the sales order item API response? A: The benefits of customizing the sales order item API response include: Including custom attributes in the API response Retrieving custom attributes along with the standard sales order item data Enhancing the flexibility and customization of the sales order item API Q: How do I troubleshoot issues with the custom resource model? A: To troubleshoot issues with the custom resource model, you can use the following steps: Check the etc/di.xml file for any errors or inconsistencies Verify that the custom resource model is properly registered in the registration.php file Use the Magento 2 debug mode to identify any errors or issues with the custom resource model Q: Can I customize the sales order item API response for other interfaces? A: Yes, you can customize the sales order item API response for other interfaces, such as the sales_order_item_search_result interface. You can follow the same steps as above to create a custom resource model and include custom attributes in the API response. Q: How do I deploy the custom module to a production environment? A: To deploy the custom module to a production environment, you need to follow the standard Magento 2 deployment process, including: Creating a new package and version for the custom module Deploying the package to the production environment Enabling the custom module in the production environment

By following these steps, you can customize the sales order item API response to include custom attributes and enhance the flexibility and customization of the sales order item API.