RE: [PHP] headers already sent and cookie problem
| From: | Ford, Mike [LSS] | Date: | Fri, 18 Jul 2003 16:19:52 +0000 |
| Subject: | RE: [PHP] headers already sent and cookie problem | ||
| Groups: | php.general | ||
| Request: | Send a blank email to php-general+get-155801@lists.php.net to get a copy of this message | ||
-----Original Message-----
From: frederik feys
To: 'Ford, Mike [LSS]'; php-general@lists.php.net
Here's the URL:
http://www.aurelis.org/store/cart.txt
and the get_cartID:
http://www.aurelis.org/store/includes/functions/get_cartID.txt
--------------------------
I've only had time for a quick look, but I think I have an inkling of where
your problem might be.
It all seems to lie with the way you've implemented GetCartId() -- and the
problem will only show up any time the cartId cookie is not already set.
Basically, if the cookie is not set, GetCartId() generates a new ID and sets
the cookie -- but this requires sending a header, and you can't do this once
you've started output of the real page. So you must make you first call to
GetCartId() *before* you send any output. Now, if we look at this fragment
of code from /store/cart.txt:
function ShowCart($lang)
{
global
$connection,$lang_dir,$DOCUMENT_ROOT,$page_theme,$country_iso_code,$srch_ter
m;
/* ob_start(); //start buffering output */
$page_title=get_label(194,$lang,$connection);
$page_tab=3;
include_once($DOCUMENT_ROOT . "/header_aurelis.php");
$country_iso_code = $_GET[country_iso_code];
if($lang=="EN"){
$currency_symbol = "$ ";
}
else{
$currency_symbol = "€ ";
}
$totalCost = 0;
$show_cart = @mysql_query(("select * from cart inner join items on
cart.itemId = items.itemId where cart.cookieId = '" . GetCartId() . "' order
by items.itemName asc"),$connection);
... we can see that you include header_aurelis.php, which presumably outputs
the initial part of your HTML, before you do
$show_cart = @mysql_query ... ;
which includes a call to GetCartId() -- which will attempt to set the cartId
cookie if it's not already set, and will fail with the "headers already
sent" error.
So, overall, I'd say you've got to get/set your cartId earlier in the game
-- and certainly before you call or include anything that outputs actual
page content.
This analysis also explains why the error is intermittent -- someone who has
set the cartId cookie once will probably not see the error again until after
the cookie expires 30 days later!
Hope this helps (and you followed my somewhat rambling explanation!)
Cheers!
Mike