根据运输国家不需要进行WooCommerce Checkout电话字段

Question

我以前看到这个问题出现了，但反向回答。 我希望问题完全按要求回答。我希望如果选择一个国家，电话号码字段可以从所需变化到可选。 我目前都需要所有国家 /地区的电话号码字段。我希望如果选择了美国，则应将电话号码更改为可选。
For reference, here is original post
https://stackoverflow.com/questions/55206672/make-woocommerce-checkout-phone-field-optional-based-on-shipping-country and below is the code to已更改为所需的国家 /地区。

// SETTINGS: The countries codes (2 capital letters) in the array
function defined_countries_for_phone_field(){
    return array( 'GB', 'JE', 'GG', 'IM' );
}

// Remove "(optional)" from non required "Billing phone" field
add_filter( 'woocommerce_form_field' , 'remove_checkout_optional_fields_label', 10, 4 );
function remove_checkout_optional_fields_label( $field, $key, $args, $value ) {

    // Get the defined countries codes
    $countries = defined_countries_for_phone_field();

    // Get Customer shipping country
    $shipping_country = WC()->customer->get_shipping_country();

    // Only on checkout page and My account > Edit address for billing phone field
    if( 'billing_phone' === $key && ( ( is_wc_endpoint_url( 'edit-address' )
    && in_array($shipping_country, $countries) ) || is_checkout() ) ) {
        $optional = '&nbsp;<span class="optional">(' . esc_html__( 'optional', 'woocommerce' ) . ')</span>';
        $field = str_replace( $optional, '', $field );
    }
    return $field;
}

// Make the billing phone field optional (by default)
add_filter( 'woocommerce_billing_fields', 'filter_billing_phone_field', 10, 1 );
function filter_billing_phone_field( $fields ) {

    // Get the defined countries codes
    $countries = defined_countries_for_phone_field();

    // Get Customer shipping country
    $shipping_country = WC()->customer->get_shipping_country();

    // Only on checkout page and My account > Edit address
    if ( ( is_wc_endpoint_url( 'edit-address' )
    && in_array($shipping_country, $countries) ) || is_checkout() )
        $fields['billing_phone']['required'] = false;

    return $fields;
}

// Real time shipping country selection actions
add_action( 'woocommerce_after_order_notes', 'custom_checkout_scripts_and_fields', 10, 1 );
function custom_checkout_scripts_and_fields( $checkout ) {
    $required = esc_attr__( 'required', 'woocommerce' );

    // Get the defined countries codes
    $countries = defined_countries_for_phone_field();

    // Hidden field for the phone number validation
    echo '<input type="hidden"  name="billing_phone_check" id="billing_phone_check" value="0">';
    $countries_str = "'".implode( "', '", $countries )."'"; // Formatting countries for jQuery
    ?>
    <script type="text/javascript">
        (function($){
            var required = '<abbr class="required" title="<?php echo $required; ?>">*</abbr>';
            var countries = [<?php echo $countries_str; ?>];
                if($('.shipping_address').is(':visible')) {
                    // ship to different country selected
                    var selectedcountry = $('#shipping_country option:selected').val();
                } else {
                    var selectedcountry = $('#billing_country option:selected').val();
                }
             //var selectedcountry = $('#shipping_country option:selected').val();
             var phoneCheck = 'input#billing_phone_check';
             var phoneField = '#billing_phone_field';

            function actionRequire( actionToDo='yes', selector='' ){
                if ( actionToDo == 'yes' ) {
                    $(selector).addClass("validate-required");
                    $(selector+' label > .required').remove();
                    $(selector+' label').append(required);
                } else {
                    $(selector).removeClass("validate-required");
                    $(selector+' label > .required').remove();
                }
                $(selector).removeClass("woocommerce-validated");
                $(selector).removeClass("woocommerce-invalid woocommerce-invalid-required-field");
            }

            // Default value Once DOM is loaded (with a 300 ms delay)
            setTimeout( function(){
                if($('.shipping_address').is(':visible')) {
                    // ship to different country selected
                    var selectedcountry = $('#shipping_country option:selected').val();
                } else {
                    var selectedcountry = $('#billing_country option:selected').val();
                }
                actionRequire( 'no', phoneField );
                if( $.inArray( selectedcountry, countries ) == -1){
                    actionRequire( 'yes',phoneField );
                    $(phoneCheck).val('1');
                }
            }, 300 );

            // Live value
            $( 'form.checkout' ).on( 'change', '#billing_country, #shipping_country, #ship-to-different-address-checkbox', function(){
                setTimeout( function(){
                    if($('.shipping_address').is(':visible')) {
                        // ship to different country selected
                        var selectedcountry = $('#shipping_country option:selected').val();
                    } else {
                        var selectedcountry = $('#billing_country option:selected').val();
                    }

                    if ( $.inArray( selectedcountry, countries ) == -1) {
                        actionRequire( 'yes' ,phoneField );
                        $(phoneCheck).val('1');
                    } else {
                        actionRequire( 'no' ,phoneField );
                        $(phoneCheck).val('0');
                    }
                }, 300 );
            });
       })(jQuery);
        </script>
    <?php
}

// Phone number validation, when the field is required
add_action('woocommerce_checkout_process', 'billing_phone_field_process');
function billing_phone_field_process() {
    // Check if set, if its not set add an error.
    if ( ! $_POST['billing_phone'] && $_POST['billing_phone_check'] == '1' )
        wc_add_notice( __( 'Please enter a number phone.' ), 'error' );
}