Squadbox plugin blank template

toolbox-plugin.php

<?php
/**
 * Plugin Name: PLUGIN_NAME_HERE
 * Plugin URI: PLUGIN_URI_HERE
 * Description: PLUGIN_DESC_HERE
 * Version: 0.0.1
 * Author: AUTHOR_HERE
 * Author URI: AUTHOR_URI_HERE
 * Text Domain: TEXT_DOMAIN_HERE
 */

if (!defined('ABSPATH')) exit();

define('SQUADBOX_PLUGIN_PATH', plugin_dir_path(__FILE__));
define('SQUADBOX_PLUGIN_URL', plugin_dir_url(__FILE__));

if (!class_exists('YourCoolClass')):

class YourCoolClass {

	public static $plugin = array(
		'name'          => 'PLUGIN_NAME_HERE',
		'version'       => '0.0.1',
		'file'          => __FILE__,
		'option_prefix' => 'acf_option_prefix_',
		'block_prefix' => 'acf_block_prefix_',
	);

	/**
	 * Constructor.
	 */
	public function setup() {
		add_action('plugins_loaded', array($this, 'includes'));
	}

	/**
	 * Includes
	 */
	public function includes() {

		// Return null if Squadbox is not active.
		if (!class_exists('Squadbox')) {
			add_action('admin_notices', array($this, 'squadbox_notice'));
			return null;
		}

		// Return if php version is below 5.5.0 or whatever version you require
		if (version_compare('5.5.0', PHP_VERSION, '>') && current_user_can('activate_plugins')) {
			add_action('admin_notices', array($this, 'php_version_notice'));
			return;
		}

		// Include license if your plugin says so
		if (Squadbox::$plugin['include_license'] !== false) {
			require_once(SQUADBOX_LOCATION_PATH.'license/class-squadbox-location-plugin-license.php');
		}

		// Includes
		include_once(SQUADBOX_LOCATION_PATH.'inc/your-other-magic-files.php');
	}

	/**
	 * Display an error notice if Squadbox is not active.
	 */
	public function squadbox_notice() {
		printf('<div class="error"><p>'.__('<strong>Squadbox</strong> is deactivated or does not exist. Please install and activate it to use <strong>'.self::$plugin['name'].'</strong>', 'squadbox').'</p></div>', PHP_VERSION);
	}

	/**
	 * Display an error notice if the PHP version is lower than your requirement
	 */
	public function php_version_notice() {
		printf('<div class="error"><p>'.__(self::$plugin['name'].' requires PHP version 5.5.0 or higher. Your server is running PHP version %s. Please contact your hosting company to upgrade your site to 5.5.0 or later.', 'squadbox').'</p></div>', PHP_VERSION);
	}
}

/**
 * Return YourCoolClass class instance.
 */
function your_cool_class() {
	global $your_cool_class;

	// Instantiate only once.
	if (!isset($your_cool_class)) {
		$your_cool_class = new YourCoolClass();
		$your_cool_class->setup();
	}
	return $your_cool_class;
}

// Instantiate.
your_cool_class();

endif; // class_exists check