Get the value of a custom checkout field in woocommerce 3 - php

Question

In Woocommerce checkout, I am adding a custom checkout field and here is my code:
add_action( 'woocommerce_before_order_notes', 'shipping_add_select_checkout_field' );
function shipping_add_select_checkout_field( WC_Checkout $checkout ) {
$options = array_merge( [ '' => __( 'Nothing to select' ), ], city_zone() );
woocommerce_form_field( 'billing_country_zone', array(
'type' => 'select',
'class' => array( 'form-row-wide', 'address-field', 'update_totals_on_change' ),
'label' => __( 'City zone' ),
'required' => true,
'options' => $options
), WC()->customer->billing_country_zone );
}
Now I am totally lost as I need to know what is WC()->customer->billing_country_zone for and how can I check it's value…
Any help is really appreciated.

Answer 1

For theWC()->customer->billing_country_zone:
First since Woocommerce 3, properties can be accessed on most all Woocommerce instances objects.
And "billing_country_zone" is no a default property of WC_Customer instance object.
As it's about checkout fields, instead you should use $checkout argument which is the instance of the WC_Checkout Object. Then there is the appropriated method get_value() to be used on it...
What is that for?
Once the customer has submitted at least one order, the selected value for "billing_country_zone" will be displayed on checkout page.
So you will have to replace the line:
), WC()->customer->billing_country_zone );
by this one:
), $checkout->get_value('billing_country_zone') );
If $checkout variable argument is not defined, you will use WC()->checkout like:
), WC()->checkout->get_value('billing_country_zone') );
Now when you will save this custom checkout field value, you will need to save it:
As order meta data
And also as User meta data
So Here is the complete code (commented):
// Display custom checkout field
add_action( 'woocommerce_before_order_notes', 'display_custom_checkout_field' );
function display_custom_checkout_field( $checkout ) {
$options = array_merge( [ '' => __( 'Nothing to select' ), ], city_zone() );
woocommerce_form_field( 'billing_country_zone', array(
'type' => 'select',
'class' => array( 'form-row-wide', 'address-field', 'update_totals_on_change' ),
'label' => __( 'City zone' ),
'required' => true,
'options' => $options
), $checkout->get_value('billing_country_zone') );
}
// custom checkout field validation
add_action( 'woocommerce_checkout_process', 'custom_checkout_field_validation' );
function custom_checkout_field_validation() {
if ( isset( $_POST['billing_country_zone'] ) && empty( $_POST['billing_country_zone'] ) )
wc_add_notice( __( 'Please select a <strong>"City zone"</strong>.', 'woocommerce' ), 'error' );
}
// Save custom checkout field value as custom order meta data and user meta data too
add_action( 'woocommerce_checkout_create_order', 'custom_checkout_field_update_order_meta', 20, 2 );
function custom_checkout_field_update_order_meta( $order, $data ) {
if ( isset( $_POST['billing_country_zone'] ) ) {
// Save custom checkout field value
$order->update_meta_data( '_billing_country_zone', esc_attr( $_POST['billing_country_zone'] ) );
// Save the custom checkout field value as user meta data
if( $order->get_customer_id() )
update_user_meta( $order->get_customer_id(), 'billing_country_zone', esc_attr( $_POST['billing_country_zone'] ) );
}
}
Code goes in function.php file of your active child theme (or active theme). tested and works.