How to override a block from a vendor to a custom module?

To override a block from a vendor module in Magento, you can follow these general steps:

1. Create a custom module: If you haven’t already, create a custom module in your Magento installation. This module will contain the overridden block and any additional customization you want to apply.
2. Identify the block to override: Determine the block class you wish to override from the vendor module. You can typically find this information in the vendor module’s code or documentation.
3. Create a new block class: In your custom module, create a new block class that extends the block you want to override. This class will serve as the replacement for the vendor’s block.

<?php

namespace YourNamespace\YourModule\Block;

use VendorNamespace\VendorModule\Block\VendorBlock;

class CustomBlock extends VendorBlock
{
    // Customizations and overrides here
}

4. Register the new block class: Create a di.xml file in your custom module’s configuration folder (e.g., YourNamespace/YourModule/etc/di.xml). Register your custom block class as a preference for the original vendor block class.

<?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="VendorNamespace\VendorModule\Block\VendorBlock" type="YourNamespace\YourModule\Block\CustomBlock" />
</config>

5. Clear caches: Flush the cache of your Magento installation to ensure the changes take effect. You can do this by running the following command in your terminal:

php bin/magento cache:flush

6. Implement your customizations: Inside your custom block class (CustomBlock), you can add or override any methods or properties as needed. This is where you customize the behavior of the block to meet your requirements.
7. Use the custom block in your layout files: Now that your custom block is registered, you can use it in your layout XML files (layout/*.xml) to replace the vendor’s block with your custom implementation. Locate the layout XML file where the vendor block is defined and update the block declaration to use your custom block class:

<block class="YourNamespace\YourModule\Block\CustomBlock" name="vendor_block_name" template="VendorNamespace_VendorModule::path/to/template.phtml" />

8. Apply additional modifications: Make any necessary changes to the template file (path/to/template.phtml) associated with the block to reflect your desired modifications.
9. Clear caches and test: Flush the cache again and test your changes to ensure that the vendor block has been successfully overridden and your customizations are applied.

Remember to update the namespaces and paths in the code examples to match your own module’s structure. These steps should help you override a block from a vendor module with your custom module in Magento, but the exact process may vary depending on your specific CMS or framework.