Remove specific parameters from a URL using PHP - php

Question

So I'm attempting to remove specific parameters from the URL query string that are predefined in an array. Here's what I have so far:
<?php
// Construct the current page URL
$host = $_SERVER['HTTP_HOST'];
$script = $_SERVER['SCRIPT_NAME'];
$params = $_SERVER['QUERY_STRING'];
$currentUrl = 'http://' . $host . $script . '?' . $params;
// Store all URL parameters into an array (HOST, PATH, QUERY, etc)
$url_params = array();
$url_params = parse_url($currentUrl);
// Create an array to store just the query string, breaking them apart
$params_array = explode('&', $url_params['query']);
// Array holding URL parameters that we want to remove
$params_to_remove = array("param1", "param2", "param3", "param4", "param5");
$location = 0;
// Loop through and remove parameters found in PARAMS_TO_REMOVE array
for($x = 0; $x < count($params_to_remove); $x++) {
if(in_array($params_to_remove[$x], $params_array)) {
$location = array_search($params_to_remove[$x], $params_array);
unset($params_array[$location]);
}
}
// Print array after unwanted parameters were removed
print_r($params_array);
echo '<br /><br />';
// Construct a new array holding only the parameters that we want
$clean_params_array = array();
for($z = 0; $z < count($params_array); $z++) {
if($params_array[$z] != '') array_push($clean_params_array, $params_array[$z]);
}
// Print clean array
print_r($clean_params_array);
echo '<br />';
// Construct the new URL
// If there are paramters remaining in URL reconstruct them
if(count($clean_params_array) > 0) {
$final_url = 'http://www.example.com' . $url_params['path'] . '?';
for($y = 0; $y < count($clean_params_array); $y++) {
$final_url .= $clean_params_array[$y] . '&';
}
// Trim off the final ampersand
$final_url = substr($final_url, 0, -1);
}
// No parameters in final URL
else $final_url = 'http://www.example.com' . $url_params['path'];
// Print final URL
echo '<br />' . $final_url;
?>
Here's the output:
Using http://www.example.com/test.php?apple&banana&orange&param1&strawberry&param2&pineapple
Array ( [0] => apple [1] => banana [2] => orange [4] => strawberry [6] => pineapple )
Array ( [0] => apple [1] => banana [2] => orange [3] => strawberry )
http://www.example.com/test.php?apple&banana&orange&strawberry
As you can see I'm losing the last parameter. I also feel as if I'm being too verbose...where am I going wrong?

Answer 1

$new_url = "http://".$_SERVER['HTTP_HOST'].$_SERVER['SCRIPT_NAME']."?".implode("&",array_diff(explode("&",$_SERVER['QUERY_STRING']),Array("param1","param2","param3","param4","param5")));
One-liner ;)
Although you'd probably be better off taking that Array(...) out of there and defining it as a variable beforehand, so it's easier to read.

Answer 2

<?php
/**
* generateURL()
*
* Sprava URL adresy
*
* #author stenley <stenley#webdev.sk>
* #version 1.4
*/
function generateURL() {
$GET = $_GET;
$QUERY_STRING = '';
$SCRIPT_NAME = substr(strrchr($_SERVER["SCRIPT_NAME"],"/"),1);
$num_args = func_num_args();
if($num_args>0 && $num_args%2==0) {
$args = func_get_args();
foreach($args as $index => $paramName) {
$paramName = trim($paramName);
if($index%2==0 && !empty($paramName)) {
$paramValue = trim($args[$index+1]);
if(array_key_exists($paramName, $GET) && empty($paramValue)) {
unset($GET[$paramName]);
} elseif(!empty($paramValue)) {
$GET[$paramName] = $paramValue;
}
}
}
}
foreach($GET as $param => $value) {
$QUERY_STRING .= $param."=".$value."&";
}
return $SCRIPT_NAME.((empty($QUERY_STRING)) ? '' : "?".substr($QUERY_STRING,0,-5));
}
?>
here is great function for managing URL address. usage is easy. here are some examples in Slovak language. but I think you will understand code samples. or I will translate it for you
sorry for my english

Answer 3

Part of the answer is in this line:
Array ( [0] => apple [1] => banana [2] => orange [4] => strawberry [6] => pineapple )
Note that $params_array[5] does not exist. Yet you try to read $params_array[5] when $z==5
(In your while loop you go through values $z = 0; => $z < 6; (count($params_array))
You can use Kolink's solution, or use a foreach loop to go through all the values:
foreach($params_array as $param) {
if($param != '') array_push($clean_params_array, $param);
}