How to make a curl request with a session to an action url?

Question

I am building a onepagecheckout for craft commerce 3. I created a custom controller to submit cart and payment info in one form submit. I'll call the default updateCart action with a curl request and send the formdata with it. This works but create a new cart eachtime instead of update the current cart in the current session. How i'll update the current cart instead of create a new one?

this is my custom action

<?php

namespace modules\modulename\controllers;

use Craft;
use craft\web\Controller;
use craft\helpers\UrlHelper;

class CheckoutController extends Controller
{

    protected $allowAnonymous = true;

    public function actionCheckout(){
        // Require POST request
        $this->requirePostRequest();
        // Get params
        $data = $this->request->post();

        try {
            $url = UrlHelper::siteUrl() . "actions/commerce/cart/update-cart";
            $curl = curl_init($url);
            curl_setopt($curl, CURLOPT_URL, $url);
            curl_setopt($curl, CURLOPT_POST, true);
            curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($curl, CURLOPT_HTTPHEADER, array('Content-Type: application/json', 'Accept: application/json'));
            curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($data));
            $resp = curl_exec($curl);
            $jsonResponse = \json_decode($resp);

            // Show error if fails
            if(!empty($jsonResponse)) {
                if($jsonResponse->success){
                    Craft::$app->session->setError($jsonResponse->message);
                } else {
                    Craft::$app->session->setError($jsonResponse->error);
                }
            } else{
                Craft::$app->session->setError('mis');
            }
            curl_close($curl);
        } catch (\Throwable $th) {
            throw $th;
        }


        $redirect = UrlHelper::siteUrl() . "webshop/checkout/onepagecheckout";
        $this->redirect($redirect);

        Craft::$app->end();
    }
}

Answer 1

You don't want to use a separate web request to call the controller action of Craft Commerce. This has numerous downsides beyond your current problem with the missing session. It will negatively impact performance, double the roundtrip time and increase the server load.

Instead, if you want to call a controller action of Craft or another plugin from one of your own controllers, you can simply do so using the craft\web\Application::runAction method. Put this in your controller:

$response = \Craft::$app->runAction('commerce/cart/update-cart');

$response will be a Response object that you can inspect to check if the action executed successfully. Or return it from your controller action to return whatever the given action returned to the client.