class-wc-connect-compatibility.php

<?php
/**
 * A class for working around the quirks and different versions of WordPress/WooCommerce
 * This is the base class. Its static members auto-select the correct version to use.
 */
namespace Automattic\WCShipping\Connect;

// No direct access please.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * WC_Connect_Compatibility class.
 */
abstract class WC_Connect_Compatibility {

	/**
	 * WC_Connect_Compatibility.
	 *
	 * @var WC_Connect_Compatibility
	 */
	private static $singleton;

	/**
	 * Woocommerce version.
	 *
	 * @var string
	 */
	private static $version = WC_VERSION;

	/**
	 * WC_Connect_Compatibility singleton instance.
	 *
	 * @return WC_Connect_Compatibility
	 */
	public static function instance() {
		if ( is_null( self::$singleton ) ) {
			self::$singleton = self::select_compatibility();
		}

		return self::$singleton;
	}

	/**
	 * Return subclass for active version of WooCommerce.
	 *
	 * @return WC_Connect_Compatibility subclass for active version of WooCommerce
	 */
	private static function select_compatibility() {
		if ( version_compare( self::$version, '6.9.0', '<' ) ) {
			require_once 'class-wc-connect-compatibility-wc30.php';

			return new WC_Connect_Compatibility_WC30();
		} else {
			require_once 'class-wc-connect-compatibility-wc69.php';

			return new WC_Connect_Compatibility_WC69();
		}
	}

	/**
	 * Overwrite default WooCommerce Version.
	 *
	 * @param string $value WooCommerce Version.
	 * @return void
	 */
	public static function set_version( $value ) {
		self::$singleton = null;
		self::$version   = $value;
	}

	/**
	 * Revert to current WooCommerce Version.
	 *
	 * @return void
	 */
	public static function reset_version() {
		self::$singleton = null;
		self::$version   = WC_VERSION;
	}

	/**
	 * Return the order admin screen
	 *
	 * @return string The order admin screen
	 */
	abstract public function get_order_admin_screen();

	/**
	 * Helper function to initialize the global $theorder object, mostly used during order meta boxes rendering.
	 *
	 * @param WC_Order|WP_Post $post_or_order_object Post or order object.
	 *
	 * @return bool|WC_Order|WC_Order_Refund.
	 */
	abstract public function init_theorder_object( $post_or_order_object );
}