Use wordpress function in PHP file - php

Question

I have a WordPress Child Theme and I use a php file as the template for a particular page.
I am trying to implement an API for a plugin called GeoIP Detection. Please see the PHP file I am using on my site below. The API I am trying to apply is "Redirect depending on country" located here
When I load the script, I am supposed to be redirected to https://www.google.com.sg However, it does not do so.
Thank you.
My PHP
<?php /* Template Name: GeoIPDetectionv3 */
add_action('template_redirect', 'geoip_redirect', 5);
function geoip_redirect(){
if (is_admin())
return;
// This condition prevents a redirect loop:
// Redirect only if the home page is called. Change this condition to the specific page or URL you need.
if (!is_page(90))
return;
if (!function_exists('geoip_detect2_get_info_from_current_ip'))
return;
$userInfo = geoip_detect2_get_info_from_current_ip();
$countryCode = $userInfo->country->isoCode;
switch ($countryCode) {
case 'DE':
$url = '/germany';
break;
case 'US':
$url = '/usa';
break;
case 'SG':
$url = 'https://www.google.com.sg';
break;
default:
$url = 'https://www.google.com.sg';
}
if ($url) {
wp_redirect(get_current_blog_id(null, $url));
exit;
}
}

Answer 1

Use a single PHP tag, and make sure the last portion of your code is in fact inside a PHP tag. Currently it is not, so it's parsed as plain text.
UPDATE: I've cleaned this up a bit for you and updated the code to reflect your revised question; i.e., following our comments below.
<?php /* Template Name: GeoIPDetectionv3 */
add_action('template_redirect', 'geoip_redirect', 5);
function geoip_redirect(){
if ( is_admin() ) {
return; // Not applicable.
}
if ( 123 !== get_current_blog_id() ) {
return; // Not on blog ID 123.
}
if ( ! is_page( 90 ) ) {
return; // Not a specific page ID on this blog.
}
if ( ! function_exists( 'geoip_detect2_get_info_from_current_ip' ) ) {
return;
}
$userInfo = geoip_detect2_get_info_from_current_ip();
$countryCode = $userInfo->country->isoCode;
switch ($countryCode) {
case 'DE':
$redirect_to = '/germany';
break;
case 'US':
$redirect_to = '/usa';
break;
case 'SG':
$redirect_to = 'https://www.google.com.sg';
break;
default:
$redirect_to = 'https://www.google.com.sg';
}
if ( ! empty( $redirect_to ) ) {
if ( stripos( $redirect_to, 'http' ) === 0 ) {
wp_redirect( $redirect_to ); // Full URL.
} else {
wp_redirect( home_url( $redirect_to ) ); // Local /path.
}
exit;
}
}