Toggling currency passing variables

[fteng]

I'm trying to add currency dropdown to choose between two currencies. Using the onchange event, I reload the page and store the value in a session variable. However, the problem is that I use a lot of forms throughout my website and I pass variables around all over the place. When the page reloads, I lose all the $_REQUEST variables because of my currency toggle. I can pass the variables one by one, but I use a lot of variables and I'm worried I may miss one.

 

Is there a better way to design the currency toggling? Any help is much appreciated.

 

Here's the code version of what I said above:

 

<form method=post action=<?=$_SERVER['PHPSELF']?>>

<select name=currency onchange="form.submit();">

  <option value=1 <?=$USD?>>U.S. Dollar</option>

  <option value=2 <?=$CAD?>>Canadian Dollar</option>

</select>

</form>

 

Note: The $USD and $CAD variables are used to store which option is SELECTED.

[fteng]

Ok I got it working. I looked up how OSCommerce does this. Essentially, I think my logic is right, just pass all the hidden variables around. Hopefully, this helps someone else who has a similar problem.

 

Here's my final code:

 

//Currency Change

if (isset($_REQUEST['currency']))

$_SESSION['currency'] = $_REQUEST['currency'];  

 

      //Default currency

if (!isset($_SESSION['currency']))

$_SESSION['currency'] = 1;

        //Go to the right place in the dropdown

if ($_SESSION['currency']==1)

$USD = "SELECTED";

else $CAD = "SELECTED";

 

        //Attach all the hidden request variables to the URL

$URL = $_SERVER['PHP_SELF'];

$hidden_request_variables = '';

foreach ($_REQUEST as $k => $v) {

                //Exclude currency since it may change

if ( ($k != 'currency') && ($k != sessionID) && ($k != 'PHPSESSID') ) {

$hidden_request_variables .= "$k=$v&";

}

}

$URL .=  "?{$hidden_request_variables}";

        //Remove the last character either & or ?

$URL = substr($URL, 0, -1);

 

<form method=post action="<?=$URL?>">

<select name=currency onchange="form.submit();">

  <option value=1 <?=$USD?>>U.S. Dollar</option>

  <option value=2 <?=$CAD?>>Canadian Dollar</option>

</select>

</form>