Cookie isn't setting, but i allow cookies - php

Question

I am trying the Post-Redirect-Get pattern.
Here are my custom functions
<?php
function ReadCookieMessage()
{
if (($_COOKIE["c"]) && ($_COOKIE["t"]))
{
$message = $_COOKIE["t"];
$message = htmlspecialchars($message);
if ($_COOKIE["c"] == "r")
{
$cssclass = 'error_msg';
}
else if ($_COOKIE["c"] == "g")
{
$cssclass = 'success_msg';
}
setcookie("c", "", time()-3600);
setcookie("t", "", time()-3600);
return '<div class="' . $cssclass . '">' . $message .'</div>';
}
}
?>
<?php
function SetCookieMessage($c,$t)
{
setcookie("c",$c, time()+3600);
setcookie("t",$t, time()+3600);
}
?>
I do SetCookieMessage("g","Your password has been changed, you may now login again"); on my change password page.
Then i do
echo ReadCookieMessage();
on my login page. I am not sure whats up. setcookie works when i set the r cookie if they check remember when they login. I also tired
setcookie("c","g", time()+3600);
setcookie("t","Your password has been changed, you may now login again", time()+3600);
in replacement for the SetCookieMessage function.
Not sure if
if ($SqlChangePass)
{
session_unset();
session_destroy();
setcookie("r", "", time()-3600);
SetCookieMessage("g","Your password has been changed, you may now login again");
header("Location: /login");
}
will be any helpful to you. Its in the changepassword script.
Php isn't giving me any errors. The goal of the functions is to set a message color(r means red and g means green) and text. Then take them to another page and read the message. The page it goes to isn't showing any sort of a message.

Answer 1

so if I get it right you execute as follows:
<?php
SetCookieMessage("something","here");
ReadCookieMessage();
?>
If this is the case, that would be normal behaviour.
Cookies are sent along with the result page in the page headers.
So you would only be able to read cookies on a next request.
e.g. First Request:
Do stuff
Place Cookie
Return result page
Second request could be:
Do stuff
Read cookie
return result page
You can read more about cookies on Wikipedia: Wikipedia page about HTTP Cookies
I quote:
The cookie is sent as a field in the header of the HTTP response by a web server to a web browser and then sent back unchanged by the browser each time it accesses that server.
I hope I understood your question correctly. And that my answer helps.

Answer 2

"I put SetCookieMessage("g","Your password has been changed, you may now login again"); echo ReadCookieMessage(); on a test page."
As Bart said, you can't set a cookie and check it on the same page.
"If i load the page, i see nothing. If i refresh the page again, i see a message. If i refresh again, i don't see the message"
On you case, that's what is happening:
You set the cookie, they're correctly set. After you set the cookie, you try to check it, but the script will not be able to see it because it was not set when it started
You reload the page, the script can now read the cookie and will display your message. But in your code, you tell the browser to expiry the cookies on ReadCookieMessage() when you set it into the past (-3600).
You reload the page, and set the cookies again and it start all over because the previous cookie has now been unset.
Check the link Bart provided! :)