script.php

<?php
/**
 * HttpHeader Plugin
 *
 * @copyright  Copyright (C) 2017 - 2019 Tobias Zulauf All rights reserved.
 * @license    http://www.gnu.org/licenses/gpl-2.0.txt GNU General Public License Version 2 or Later
 */

defined('_JEXEC') or die;

use Joomla\CMS\Installer\InstallerScript;

/**
 * Installation class to perform additional changes during install/uninstall/update
 *
 * @since  1.0
 */
class PlgSystemHttpHeaderInstallerScript extends InstallerScript
{
	/**
	 * Extension script constructor.
	 *
	 * @since   1.0
	 */
	public function __construct()
	{
		// Define the minumum versions to be supported.
		$this->minimumJoomla = '3.8';
		$this->minimumPhp    = '7.0';

		$this->deleteFiles = array(
			'/plugins/system/httpheader/subform/keyvalue.xml',
			'/plugins/system/httpheader/subform/cspkeyvalue.xml',
			'/plugins/system/httpheader/subform/customhttpheaders.xml',
		);

		$this->deleteFolder = array(
			'/plugins/system/httpheader/subform/',
		);
	}

	/**
	 * Function to perform changes during postflight
	 *
	 * @param   string            $type    The action being performed
	 * @param   ComponentAdapter  $parent  The class calling this method
	 *
	 * @return  void
	 *
	 * @since   1.0.1
	 */
	public function postflight($type, $parent)
	{
		$this->removeFiles();
	}
}