Remove a value from a querystring

Question

I have a URL in which a querystring is produced by a PHP script. Various values are displayed in the querystring.

Basically, I need to remove a specific value from the query string when a visitor clicks on a link or a 'remove' button.

So, the querystring looks like this:

http://www.foo.com/script.php?bar1=green&bar2=blue

But when a link or 'remove' button is clicked by a user, bar1=green is removed, and the visitor is directed to the following URL:

http://www.foo.com/script.php?bar2=blue

I thought this would be easy using basic HTML with a form or anchor but I haven't been able to do it so far.

Just so you know, i do not have access to the code on the PHP script itself; it is hosted remotely and is called to my webpage by a PHP wrapper using an iframe.

Any suggestions greatly appreciated.

Many thanks,

Matt

Based on the description, you will need to have access to the PHP code to do what you are trying to do. Do you have a an actual URL we can look at? It may help us better understand what you are looking for. — Chuck Burgess, Nov 20 '10 at 16:22

score 4 · Accepted Answer · answered Nov 20 '10 at 16:31

4

You can remove the value from the query string using this code:

<?php
function parseQueryString($url,$remove) {
    $infos=parse_url($url);
    $str=$infos["query"];
    $op = array();
    $pairs = explode("&", $str);
    foreach ($pairs as $pair) {
       list($k, $v) = array_map("urldecode", explode("=", $pair));
        $op[$k] = $v;
    }
    if(isset($op[$remove])){
        unset($op[$remove]);
    }

    return str_replace($str,http_build_query($op),$url);

} 
echo parseQueryString( "http://www.foo.com/script.php?bar1=green&bar2=blue","bar2");
?>

answered Nov 20 '10 at 16:31

ynh

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Thanks for the response. I tried this but I couldn't get it to work. I think a simple html form button would be more appropriate than PHP? – Matt Nov 20 '10 at 18:31
you need to have php5 on your server – ynh Nov 20 '10 at 18:33
How do I make this dynamic, in the sense that echo parseQueryString() equals the current query string in the URL? – Matt Nov 20 '10 at 18:59
echo parseQueryString("http://" . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'],"bar2"); – ynh Nov 20 '10 at 19:11
Brilliant, got this to work! Your code returns the query string minus the variable, so, surrounding your code by a html anchor returns the URL + querystring minus the variable. Thanks for your help! – Matt Nov 20 '10 at 19:33
I have posted a follow up question to this here. – Matt Nov 21 '10 at 13:35

Remove a value from a querystring

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