How to override Gantry 5 library classes

General
1

I would like to extend the gantry5 library files in Joomla, specifically the Platform class which can found in the file src/classes/Gantry/Framework/Platform.php. I want to be able to extend this file so I can add additional domains to the finder function so that that Gantry5 particles can be used with other components such as Hikashop.

Reading the documentation Creating Custom File Overrides | Gantry Documentation it says:

PHP classes found in /libraries/gantry5 can also be overridden, but as they need to be autoloaded, this requires some additional manual intervention involving adding a loader for classes.

Can anyone expand on how a loader for the class overrides should be implemented?

2

To override and extend Gantry 5 library classes in Joomla, you need to create custom class overrides and register them with Joomla’s autoloader. Here’s how to do it, step-by-step:

1. Create a Custom Override Directory

First, create a custom override directory in your Joomla template or a separate plugin. For example:

  • If you’re working within a Joomla template (e.g., my-template), create an override directory:
<?php

namespace Gantry\Framework;

use Gantry\Framework\Platform as BasePlatform;

class CustomPlatform extends BasePlatform
{
    // Override or extend methods here
    public function finder($type, $identifier)
    {
        // Custom logic here
        return parent::finder($type, $identifier);
    }
}

4. Create a Loader for the Custom Class

Since Gantry 5 classes are autoloaded, you need to add a custom loader to replace the original class with your extended class. This can be done by creating a plugin or modifying the index.php of your template. Here’s an example of how to create a loader:

  • Create a custom.php file in your template’s root directory (e.g., /templates/my-template/custom.php):
<?php
defined('_JEXEC') or die;

// Register the custom loader
spl_autoload_register(function ($class) {
    $classMap = [
        'Gantry\\Framework\\Platform' => JPATH_THEMES . '/my-template/custom/overrides/Gantry/Framework/CustomPlatform.php'
    ];

    if (isset($classMap[$class])) {
        include $classMap[$class];
    }
});

This code registers an autoloader that maps the original Gantry 5 class (Gantry\Framework\Platform) to the custom override class (CustomPlatform.php).

5. Test the Override

After setting up the custom loader, test your site to ensure that the custom CustomPlatform class is being used. You can do this by placing some debugging code (like echo or var_dump) in your custom class to verify that it is being loaded.

Additional Notes

  • If you are overriding more than one class, expand the $classMap array in the custom loader.
  • Always clear Joomla’s cache after making changes to custom files to ensure the changes are picked up.
  • If you prefer a more organized approach, consider creating a Joomla plugin (e.g., a system plugin) that includes the custom autoloader instead of modifying the template’s index.php.

By following these steps, you should be able to override and extend Gantry 5 library classes in Joomla. This method uses Joomla’s and PHP’s autoloading mechanisms to replace the Gantry 5 core classes with your custom implementations.