How can I set default zip code for checkout page and refresh shipping methods?

Question

I created module for set default zip code in checkout page by this answer - https://magento.stackexchange.com/a/293818/102895. It's work - the ZIP code is set when the page loads by this plugin.

But shipping methods not refresh. How can I set default zip code and refresh shipping methods in checkout page during load page?

Answer 1

try this, Update LayoutProcessor.php

app\code\Ketan\Module\Plugin\Block\LayoutProcessor.php

<?php
namespace Ketan\Module\Plugin\Block;

class LayoutProcessor
{
    protected $checkoutSession;

    public function __construct(
        \Magento\Checkout\Model\Session $checkoutSession
    ) {
        $this->checkoutSession = $checkoutSession;
    }

    /**
     * @param \Magento\Checkout\Block\Checkout\LayoutProcessor $subject
     * @param array $jsLayout
     * @return array
     */
    public function afterProcess(
        \Magento\Checkout\Block\Checkout\LayoutProcessor $subject,
        array $jsLayout
    ) {
        $postcode = 369856;
        $quote = $this->checkoutSession->getQuote();
        $shippingAddress = $quote->getShippingAddress();

        // Update the shipping address with the custom zip code
        $shippingAddress->setPostcode($postcode);

        $quote->save();
        /*================Start For Shipping Address ===========*/

        if(isset($jsLayout['components']['checkout']['children']['steps']['children']['shipping-step']['children']
            ['shippingAddress']['children']['shipping-address-fieldset'])) {

            $jsLayout['components']['checkout']['children']['steps']['children']['shipping-step']
            ['children']['shippingAddress']['children']['shipping-address-fieldset']['children']['postcode']['value'] = $postcode;

        }

        /*================End For Shipping Address ===========*/




        /*================Start For Billing Address ===========*/
        if(isset($jsLayout['components']['checkout']['children']['steps']['children']['billing-step']['children']
            ['payment']['children']['payments-list'])) {
            $paymentsList = $jsLayout['components']['checkout']['children']['steps']['children']['billing-step']['children']
            ['payment']['children']['payments-list']['children'];

            foreach ($paymentsList as $paymentCode => $payment) {
                if(strpos($paymentCode, '-form') === false) {
                    continue;
                }
                $jsLayout['components']['checkout']['children']['steps']['children']['billing-step']['children']
                ['payment']['children']['payments-list']['children'][$paymentCode]['children']['form-fields']['children']['postcode']['value'] = $postcode;
            }
        }
         if(isset($jsLayout['components']['checkout']['children']['steps']['children']['billing-step']['children'])){


            $jsLayout['components']['checkout']['children']['steps']['children']['billing-step']['children']
            ['payment']['children']['afterMethods']['children']['billing-address-form']['children']['form-fields']['children']['postcode']['value'] = $postcode;

        }

        /*================End For Billing Address ===========*/
        return $jsLayout;
    }

}