How to pass info from one page to another with cookies using php

Question

Possible Duplicate:
“Warning: Headers already sent” in PHP

<?php
 session_start(); 

 $_SESSION['page'] = "test.php";

 echo "Page to load in iframe = ". $_SESSION['page']; 

 setcookie('PagetoShow', $_SESSION); 

 if(isset($_COOKIE['PagetoShow']))
$Page = $_COOKIE['PagetoShow']; 
echo "Page to load in iframe = ". $Page;
 else
$Page="welcome.php"

 ?>

I guess it is a syntax error, but I know too little or nothing php to find it. What is wrong?

score 2 · Accepted Answer · answered Nov 13 '12 at 22:05

<?php
 session_start(); 

 $_SESSION['page'] = "test.php";

Good, at least you don't forget to run session_start() before setting a session key.

 echo "Page to load in iframe = ". $_SESSION['page']; 

 setcookie('PagetoShow', $_SESSION);

This is problematic. Cookies are sent in a header field, but you flushed the headers already by echo-ing something.

 if(isset($_COOKIE['PagetoShow']))
$Page = $_COOKIE['PagetoShow']; 
echo "Page to load in iframe = ". $Page;
 else
$Page="welcome.php"

There is a syntax error here, you need to add parentheses for the if-body:

if(isset($_COOKIE['PagetoShow'])) {
    $Page = $_COOKIE['PagetoShow']; 
    echo "Page to load in iframe = ". $Page;
}

Some documentation:

http://php.net/if
http://php.net/setcookie (note Like other headers, cookies must be sent before any output from your script (this is a protocol restriction))
http://www.php.net/manual/en/function.error-reporting.php (see also its See also section)

score 0 · Answer 2 · answered Nov 13 '12 at 21:52

0

The second argument to setcookie needs to be a string - you're passing an array ($_SESSION). You can do:

 $_SESSION['page'] = "test.php"; 

 setcookie('PagetoShow', $_SESSION['page']); // <-- this is the only change needed

 if(isset($_COOKIE['PagetoShow']))
   $Page = $_COOKIE['PagetoShow']; 
   echo "Page to load in iframe = ". $Page;
 else
   $Page="welcome.php"

answered Nov 13 '12 at 21:52

swatkins

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it doesn't matter if it is a string, the cookie is still set (`page=Array`). The problem is that something is already printed and therefore the cookie header cannot be sent. – Lekensteyn Nov 13 '12 at 21:53
Oh, makes sense. i've updated my answer to fix that "header cannot be sent" error. – swatkins Nov 13 '12 at 21:54
Even though he calls setcookie on that page, the cookie won't be available until the next page request. I think that might be his confusion. – Kyle Nov 13 '12 at 21:56
@Kyle - good point - I guess I was assuming it was separate requests (the reason to use cookies in the first place) – swatkins Nov 13 '12 at 21:57
Thanks for the info on that the cookie isn't available until the next page request, for I had it all on one page just for testing purposes. But it still doesn't work, I get a 500 error message – Chatrine Karima Nov 13 '12 at 22:01
Well then, we'll have to see some more code. – swatkins Nov 14 '12 at 13:47

How to pass info from one page to another with cookies using php

2 Answers2