WooCommerce conditional custom checkout fields

Question

In WooCommerce, I\'m currently trying to add a conditional custom field in the Checkout that shows a checkbox which if is checked displays an input field to insert an italia

Answer 1

In this answer I can't treat PDF invoice, so you will get here:

• Solving the problem of conditional "required" field (point 1)
• Solving the problem of the json error (point 2)
• Displayed only for italian language (point 3)

Additionally I have:

• Revisited all your code and corrected many little errors.
• Added code to display and edit the backend user profile custom field value "codice fiscale":
  
  

Here is the code:

add_filter( 'woocommerce_checkout_fields' , 'cbi_cf_chkbox' );
function cbi_cf_chkbox ( $fields ) {
    if ( ICL_LANGUAGE_CODE !='it' ) return $fields; // Only for Italy

    $fields['billing']['checkbox_cf'] = array(
        'type'      => 'checkbox',
        'label'     => __('Voui la fattura? (solo per privati)', 'cbi-custom-parts'),
        'class'     => array('form-row-wide'),
        'clear'     => true
     );

    $fields['billing']['cf_in'] = array(
        'label'     => __('Inserisci il codice fiscale', 'cbi-custom-parts'),
        'placeholder'   => _x('RSSMRA85T10A562S', 'placeholder', 'cbi-custom-parts'),
        'class'     => array('form-row-wide'),
        'clear'     => true
     );

    return $fields;
}

add_action( 'woocommerce_after_checkout_form', 'cbi_cf_conditionally_hide_show', 6);
function cbi_cf_conditionally_hide_show() {
    if ( ICL_LANGUAGE_CODE !='it' ) return; // Only for Italy
    $required = esc_attr__( 'required', 'woocommerce' );
    ?>
    
    user_id, 'codice_fiscale', sanitize_text_field( $_POST['cf_in'] ) );

    update_post_meta( $order_id, '_codice_fiscale', sanitize_text_field( $_POST['cf_in'] ) );
}

// Backend : Display in Order edit pages, after billing address, the custom field value "codice fiscale"
add_action( 'woocommerce_admin_order_data_after_billing_address', 'cbi_cf_admin_order_data_after_billing_address', 10, 1 );
function cbi_cf_admin_order_data_after_billing_address( $order ){
    $codice_fiscale = get_post_meta( $order->get_id(), '_codice_fiscale', true );
    if( ! empty( $codice_fiscale ) )
        echo '
'.__('Codice Fiscale', 'cbi-cf-invoice').': ' . $codice_fiscale . '
';
}

// Backend: Display and edit user profile custom field value "codice fiscale" Only for Italy
add_action( 'show_user_profile', 'add_extra_user_codice_fiscale', 1, 1 );
add_action( 'edit_user_profile', 'add_extra_user_codice_fiscale', 1, 1 );
function add_extra_user_codice_fiscale( $user )
{

    //if( get_user_meta( $user->ID, 'billing_country', true ) != 'IT' ) return;  // Only for Italy
    $codice_fiscale = get_user_meta( $user->ID, 'codice_fiscale', true );
    if( empty( $codice_fiscale ) ) $codice_fiscale = '';
    ?>
        

        

    

Code goes in function.php file of your active child theme (or theme) or also in any plugin file.

All code is tested on Woocommerce 3+ and works.