force_shipping_method.php

<?php

/**
 * Plugin Name:       اقدام گروهی به تغییر شیوه‌ی ارسال
 * Plugin URI:        https://baransys.com/
 * Description:       با استفاده از این افزونه می‌توان با یک کلیک شیوه‌ی ارسال را به نوع دیگری تغییر داد.
 * Version:           1.0
 * Requires at least: 5.2
 * Requires PHP:      7.2
 * Author:            Reza Esmaeili
 * Author URI:        https://rezaesmaeili.ir/
 * License:           GPL v2 or later
 * License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 * Update URI:        https://baransys.com/
 */

/*
 * Custom bulk action in dropdown
 * @since 3.5.0
 */

add_filter('bulk_actions-edit-shop_order', 'baran_register_bulk_action'); // edit-shop_order is the screen ID of the orders page
function baran_register_bulk_action ($bulk_actions)
{
	$bulk_actions['mark_pishtaz_shipment'] = 'Force shipment to Pishtaz Post'; // <option value="mark_awaiting_shipment">Mark awaiting shipment</option>
	return $bulk_actions;
}

add_action('admin_action_mark_pishtaz_shipment', 'baran_bulk_process_custom_status'); // admin_action_{action name}
function baran_bulk_process_custom_status ()
{

	// if an array with order IDs is not presented, exit the function
	if (!isset($_REQUEST['post']) && !is_array($_REQUEST['post']))
		return;

	foreach ($_REQUEST['post'] as $order_id) {
		$order = new WC_Order($order_id);
		$shippings = $order->get_shipping_methods(); // same thing than $order->get_items('shipping')

		foreach ($shippings as $ship) {
			$ship->set_method_title("پست تاپین - پیشتاز (رایگان جشنواره‌ای)");
			$ship->set_method_id('Tapin_Pishtaz_Method'); // set an existing Shipping method rate ID
			$ship->set_instance_id(9);
		}
		$order->save();
	}

	// of course using add_query_arg() is not required, I could've built my URL inline
	$location = add_query_arg(array(
		'post_type' => 'shop_order',
		'mark_pishtaz_shipment' => 1, // mark_pishtaz_shipment=1 is just the $_GET variable for notices
		'changed' => count($_REQUEST['post']), // number of changed orders
		'ids' => join(',', $_REQUEST['post']),
		'post_status' => 'all'
	), 'edit.php');

	wp_redirect(admin_url($location));
	exit;
}

/*
 * Notices
 */
add_action('admin_notices', 'baran_custom_order_status_notices');
function baran_custom_order_status_notices ()
{

	global $pagenow, $typenow;

	if ($typenow == 'shop_order'
		&& $pagenow == 'edit.php'
		&& isset($_REQUEST['mark_pishtaz_shipment'])
		&& $_REQUEST['mark_pishtaz_shipment'] == 1
		&& isset($_REQUEST['changed'])) {

		$message = sprintf(_n('شیوه ارسال به پیشتاز تغییر نمود.', 'شیوه‌ی ارسال %s سفارش به پیشتاز تغییر نمود.', $_REQUEST['changed']), number_format_i18n($_REQUEST['changed']));
		echo "<div class=\"updated\"><p>{$message}</p></div>";

	}
}

?>