Check URL parameter in php - php

Question

I want to check a parameter in a url variable, for example:
$var2join = 'en'; // can be anything else
$url = 'https://www.example.com/hello/parameter2';
$url2 = 'https://www.example.com/hello2';
$url3 = 'https://www.example.com/en/hey';
first check if the $url vars have the $var2join into $var as parameter if have it, leave it intact and if not add it.
Wanted output:
$url = 'https://www.example.com/en/hello/parameter2';
$url2 = 'https://www.example.com/en/hello2';
$url3 = 'https://www.example.com/en/hey';
I tried:
$url = (!preg_match('~^/[a-z]{2}(?:/|$)~', $location)) ? '/' . $var2join . $url : $url;

Answer 1

Use parse_url(), it is specifically for analysing URLs and their various elements.
Note this code assumes your parameters are path segments, as you describe above. If you ever use query string parameters like ?foo=bar, you'd need to adjust.
$var2join = 'en';
$url = 'https://www.example.com/hello/parameter2';
// Split URL into each of its parts
$url_parts = parse_url($url);
// Create an array of all the path parts, which correspond to
// parameters in your scheme
$params = explode('/', $url_parts['path']);
// Check if your var is in there
if (!in_array($var2join, $params)) {
// If not, reconstruct the same URL, but with your var inserted.
// NOTE this assumes a pretty simple URL, you'll need to adjust if
// you ever have other elements like port number, u/p, query strings
// etc. #Jason-rush links to something in the PHP docs to handle
// such cases.
$url = $url_parts['scheme'] . '://' . $url_parts['host'] . '/' . $var2join . $url_parts['path'];
}
// Check your result - https://www.example.com/en/hello/parameter2
echo $url;

Answer 2

This is a little generic function with some support code to give you some ideas... Not very elegant but it works.
<?php
$base_url = 'https://www.example.com/';
$var2join = 'en'; // can be anything else
$url = $base_url . 'hello/parameter2';
$url2 = $base_url . 'hello2';
$url3 = $base_url . 'en/hey';
$url4 = $base_url . 'hey/this/is/longer';
echo prepend_path_to_url($base_url, $url, $var2join);
echo '<br>';
echo prepend_path_to_url($base_url, $url2, $var2join);
echo '<br>';
echo prepend_path_to_url($base_url, $url3, $var2join);
echo '<br>';
echo prepend_path_to_url($base_url, $url4, $var2join);
echo '<br>';
/**
* Prepend a Path to the url
*
* #param $base_url
* #param $url
* #param $path_to_join
* #return string
*/
function prepend_path_to_url($base_url, $url, $path_to_join) {
// Does the path_to_join exist in the url
if (strpos($url, $path_to_join) === FALSE) {
$url_request = str_replace($base_url,'',$url);
$url = $base_url . $path_to_join . '/'. $url_request;
}
return $url;
}