Magento 2. Populate New Billing Address Form with default billing address values

Question

If a customer has a default billing address I would want to populate the checkout > billing step > new address > form with the those values.

I found all the html and JavaScript files that are used to generate the billing step. I would prefer to do this from php.

Where to start. Any advice?

Answer 1

I guess following mixin for Magento_Checkout/js/view/payment will do what you want (doing this in php won't work in my opinion):

define(
    [
        'Magento_Checkout/js/action/get-payment-information',
        'Magento_Checkout/js/model/quote',
        'Magento_Customer/js/model/customer',
    ], function (
        getPaymentInformation,
        quote,
        customer) {
        'use strict';

        var mixin = {

            initialize: function () {
                getPaymentInformation();

                this._super();

                quote.billingAddress(customer.getBillingAddressList()[0]);

                return this;
            }
        };

        return function (target) {
            return target.extend(mixin);
        };
    }
);