For WooCommerce 3+ (update):
Since WooCommerce 3.0 checkout fields have changed a little bit so is not possible to reorder fields as before.
There is a new 'priority' argument that handle fields order, for checkout fields and my account fields as well.
Below I am just updating the part related to ordering fields:
## 3. Ordering the billing fields
// Set the order of the fields
$billing_fields_new_order = array(
'billing_first_name', 'billing_last_name', 'billing_email',
'billing_phone', 'billing_address_1', 'billing_address_2',
'billing_postcode', 'billing_city', 'billing_country',
'billing_status',
'billing_company', 'billing_number_id', 'billing_ser_id'
);
$count = 0;
$priority = 10;
// Updating the 'priority' argument
foreach($billing_fields_new_order as $field_name){
$count++;
$fields['billing'][$field_name]['priority'] = $count * $priority;
}
// END: returning the customized checkout fields
return $fields;
Reference: Reordering checkout fields in WooCommerce 3
Original answer:
Here is a solution with a jQuery/JS script to make working the conditional mechanism just as you expect… The php code is completed with some necessaries functions…
PHP code (goes in function.php):
// Registering external jQuery/JS file
function cfields_scripts() {
/* IMPORTANT NOTE: For a child theme replace get_template_directory_uri() by get_stylesheet_directory_uri()
The external cfields.js file goes in a subfolder "js" of your active child theme or theme.*/
wp_enqueue_script( 'checkout_script', get_template_directory_uri().'/js/cfields.js', array('jquery'), '1.0', true );
}
add_action( 'wp_enqueue_scripts', 'cfields_scripts' );
add_filter( 'woocommerce_checkout_fields', 'custom_checkout_billing_fields' );
function custom_checkout_billing_fields( $fields ) {
// 1. Creating the additional custom billing fields
// The "status" selector
$fields['billing']['billing_status']['type'] = 'select';
$fields['billing']['billing_status']['class'] = array('form-row-wide, status-select');
$fields['billing']['billing_status']['required'] = true;
$fields['billing']['billing_status']['label'] = __('User status', 'my_theme_slug');
$fields['billing']['billing_status']['placeholder'] = __('Chose an option', 'my_theme_slug');
$fields['billing']['billing_status']['options'] = array(
'1' => __( 'Individual', '' ),
'2' => __( 'Company', '' )
);
// Customizing 'billing_company' field ['required']
$fields['billing']['billing_company']['required'] = false;
$fields['billing']['billing_company']['class'] = array('form-row-wide', 'status-group2');
// The "Number ID" text field
$fields['billing']['billing_number_id']['type'] = 'text';
$fields['billing']['billing_number_id']['class'] = array('form-row-wide');
$fields['billing']['billing_number_id']['required'] = true;
$fields['billing']['billing_number_id']['label'] = __('Number ID', 'my_theme_slug');
$fields['billing']['billing_number_id']['placeholder'] = __('Enter your Number ID', 'my_theme_slug');
// The "Serial identification" text field
$fields['billing']['billing_ser_id']['type'] = 'text';
$fields['billing']['billing_ser_id']['class'] = array('form-row-wide', 'status-group2');
$fields['billing']['billing_ser_id']['required'] = false;
$fields['billing']['billing_ser_id']['label'] = __('Serial identification', 'my_theme_slug');
$fields['billing']['billing_ser_id']['placeholder'] = __('Enter your Serial identification', 'my_theme_slug');
// 3. Ordering the billing fields
$fields_order = array(
'billing_first_name', 'billing_last_name', 'billing_email',
'billing_phone', 'billing_address_1', 'billing_address_2',
'billing_postcode', 'billing_city', 'billing_country',
'billing_status',
'billing_company', 'billing_number_id', 'billing_ser_id'
);
foreach($fields_order as $field) $ordered_fields[$field] = $fields['billing'][$field];
$fields['billing'] = $ordered_fields;
// Returning Checkout customized billing fields
return $fields;
}
// Process the checkout
add_action('woocommerce_checkout_process', 'my_custom_checkout_field_process');
function custom_checkout_field_process() {
// Check if set, if its not set add an error.
if ( ! $_POST['billing_number_id'] )
wc_add_notice( __( 'Please enter your Number ID.', 'my_theme_slug' ), 'error' );
if ( ! $_POST['billing_ser_id'] )
wc_add_notice( __( 'Please enter your Serial id.' , 'my_theme_slug' ), 'error' );
}
// Update the order meta with field value
add_action( 'woocommerce_checkout_update_order_meta', 'custom_checkout_field_update_order_meta' );
function custom_checkout_field_update_order_meta( $order_id ) {
if ( ! empty( $_POST['billing_number_id'] ) )
update_post_meta( $order_id, 'billing_number_id', sanitize_text_field( $_POST['billing_number_id'] ) );
if ( ! empty( $_POST['billing_ser_id'] ) )
update_post_meta( $order_id, 'billing_ser_id', sanitize_text_field( $_POST['billing_ser_id'] ) );
}
// Display field value on the order edit page
add_action( 'woocommerce_admin_order_data_after_billing_address', 'custom_checkout_field_display_admin_order_meta', 10, 1 );
function custom_checkout_field_display_admin_order_meta($order){
echo '<p><strong>'.__('My number ID').':</strong> ' . get_post_meta( $order->id, 'billing_number_id', true ) . '</p>';
echo '<p><strong>'.__('My serial identification').':</strong> ' . get_post_meta( $order->id, 'billing_ser_id', true ) . '</p>';
}
Javascript cfields.js
code (external file):
// This file named "cfields.js" goes in a subfolder "js" of your active child theme or theme
jQuery(document).ready(function($){
$('#billing_company_field').hide(function(){
$(this).removeClass("validate-required");
});
$('#billing_ser_id_field').hide(function(){
$(this).removeClass("validate-required");
});
$("#billing_number_id_field").addClass("validate-required");
$("#billing_status").change(function(){
if($("#billing_status option:selected").val() == "2"){
$('#billing_company_field').show(function(){
$(this).addClass("validate-required");
});
$('#billing_ser_id_field').show(function(){
$(this).addClass("validate-required");
});
} else if($("#billing_status option:selected").val() == "1"){
$('#billing_company_field').hide(function(){
$(this).removeClass("validate-required");
});
$('#billing_ser_id_field').hide(function(){
$(this).removeClass("validate-required");
});
}
});
});
All this code has been tested and works