function conditional_checkout_field($checkout)
{
echo '<div id="conditional_checkout_field">';
$check_in_cart = conditional_product_in_cart('FND');
//replace xxxx with the product id
// Check if the product is in the cart and show the custom fields if it is
if ($check_in_cart === true) {
woocommerce_form_field('custom_field', array('type' => 'text', 'class' => array('my-field-class form-row-wide'), 'label' => __('Friday Night Dinner Seating <br /><span class="extrainfo">Provide the total number of guests in your party, as well as their names if they are purchasing their tickets in a separate order</span>'), 'placeholder' => __('Name and number of people in party'), 'required' => true), $checkout->get_value('custom_field'));
}
}
function conditional_checkout_field_process()
{
$pid = get_option('oizuled_conditional_fields_pid');
$check_in_cart = conditional_product_in_cart($pid);
// Check if the field is required and set, if not then show an error message.
if ($check_in_cart == true && get_option('oizuled_conditional_fields_required') == 'yes' && !$_POST['conditional_field']) {
wc_add_notice(__(get_option('oizuled_conditional_fields_requiredtext')), 'error');
}
}