Programmatically adding product attributes

In the recipe Creating an install and upgrade script, we learned how we can automate the execution of database changes.

In these install scripts, we can also add attributes to products, as we will learn in this recipe.

Getting ready

We will work further on the Packt_HelloWorld module that we have created in the previous recipes. Make sure you have the module installed.

How to do it...

The following steps describe the procedure to create an upgrade script that adds a product attribute to all products:

1. The module Packt_HelloWorld is already installed in our system so we have to create an upgrade script. Create the file UpgradeData.php in the folder app/code/Packt/HelloWorld/Setup. Add the following content in that file:

   <?php
   namespace Packt\HelloWorld\Setup;
   
   use Magento\Framework\Setup\UpgradeDataInterface;
   use Magento\Framework\Setup\ModuleContextInterface;
   use Magento\Framework\Setup\ModuleDataSetupInterface;
   
   class UpgradeData implements UpgradeDataInterface...