Redirect to current URL, but replace string? - php

Question

So I have a working redirect that currently sends customers to my homepage if they select a different city from a drop-down select. This changes some custom user meta data and uses that to determine when a redirect should occur. Simple enough.
if ( is_user_logged_in() && $metalocation_display !== 'chicago' && strpos($url,'chicago') == true) {
header('Location: example.com');
}
if ( is_user_logged_in() && $metalocation_display == 'chicago' && strpos($url,'chicago') == false) {
header('Location: example.com/chicago/');
}
What I would like to achieve is, if the customer is on the shop page, the I can redirect them to the CURRENT page they are on (not the homepage), but simply replace the city name with strpos or something similar... basically call the current URL and only replace the name of the city, regardless of where in the URL that string is.
Something like:
if ( is_user_logged_in() && $metalocation_display !== 'chicago' && strpos($url,'chicago') == true) {
header('Location: example.com');
}
if ( is_user_logged_in() && $metalocation_display == 'chicago' && strpos($url,'chicago') == false) {
header('Location: GET CURRENT URL & REPLACE CURRENT CITY (using a list of cities) OR ADD 'CHICAGO' AFTER DOMAIN IF ONE DOESN'T EXIST ');
}
Any advice?

Answer 1

Something like this should work (remove type declarations if using < PHP 7+):
function get_current_url( array $cities, string $target_city ): string {
// Get protocol.
$url = ( $_SERVER['HTTPS'] === 'on' ? 'https://' : 'http://' );
// Get URL parts.
$port = $_SERVER['SERVER_PORT'];
$name = $_SERVER['SERVER_NAME'];
$uri = $_SERVER['REQUEST_URI'];
// Check all cities in the array and replace if found.
foreach ( $cities as $city ) {
$uri = str_replace( $city, $target_city, $uri );
}
// Build URL with matching port.
$url .= ( $port !== '80' ? $name . ':' . $port . $uri : $name . $uri );
// Return escaped URL.
return esc_url( $url );
}
And then in your code:
if ( is_user_logged_in() && $metalocation_display !== 'chicago' && strpos($url,'chicago') == true) {
header('Location: example.com');
}
// Fill array with possible cities.
$cities = array( 'london', 'new-york', );
if ( is_user_logged_in() && $metalocation_display == 'chicago' && strpos($url,'chicago') == false) {
header('Location: ' . get_current_url( $cities, 'chicago' ) );
}
Obviously be sure to prefix the function though.