asked on

cookie on php file

Dear Experts,
I set cookie of "ticker" by setcookie() in php that is really easy as follows code
But the strange thing is that why it will echo out the correct result
of cookie ticker to be 'testing" after press refresh button on browser
I mean it won't echo out the result in first time run the php file after
I clear up all cookie on browser for testing. it always only echo out
the result after first run php file and run it again at second time(like refresh the page)
Is it related to php version isssue or apache linux server? As remember it won't happen in the past and it is as easy as shown at
http://php.net/setcookie

Please advise
Duncan

<?php
setcookie("ticker",'testing');
echo $_COOKIE['ticker']."=====<br/>";
?>

Open in new window

SOLUTION

Ray Paseur

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

duncanb7

ASKER

So you mean what I experienced is normal and correct that I only echo out
the result of cookie at second time of http request, Right ?

duncanb7

ASKER

I try to fix the issue by adding header to the same location of the php file of cookie.php
but it will report to warning
Warning: Cannot modify header information - headers already sent by (output started at /mysite/cookie.php:3) in /mysite/test.php on line 4

How to avoid the warning beside using @ on header() ? Why it will give me the warning
, what special reason behind for checking echo statement on header() function ?
it seems the warning is not harmful or risky to my code but I want to know the reason.

I will read your good article definitely later on. But I need to finish my work first

Please advise & thanks

Duncan

cookie.php file
===============

<?php
setcookie("ticker",'testing');
echo $_COOKIE['ticker']."=====<br/>";
header("location: http://mysite.com/cookie.php");
?>

Open in new window

ASKER CERTIFIED SOLUTION

Ray Paseur

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

Ray Paseur

One other note... The use of @ in a function call is a code smell, and is to be avoided. It does not suppress the error, it only suppresses the error message; in other words, the error still happened and you just don't know about it. This is one of the many stupid and dangerous things about the PHP language. Such a capability should not even exist. Just don't do that.
https://www.experts-exchange.com/Web_Development/Web_Languages-Standards/PHP/A_12293-AntiPHPatterns-and-AntiPHPractices.html

duncanb7

ASKER

my issue is fixed with the following code by isset() and header() but it need
do two times HTTP request that may be slower in speed felt by page viewer
Any idea is better than this code ?

Duncan

main.php
==============

<?php
setcookie("ticker",'testing');
if (isset($_COOKIE['ticker'])) { 
/* ticker cookie is set  so do other php code here */
 }
 else header("location:main.php"]
?>
<html>
<body>
</body>
......code html here
</html>

Open in new window

duncanb7

ASKER

Thanks for your reply and good articles, if you have time, please give me some advise on my last post. Use session, session_start(); $_SEESION['ticker']="testing" instead of cookie ? if so, but
session expire time is hard to be controlled in php.ini file

Duncan

Ray Paseur

Two HTTP requests will always be slower than one, but before you worry about that part, use a timer to determine how much slower. It may not matter.

Here is the code snippet from the last post above, annotated with comments. It does not really make sense as written. If you want to post a question that describes what you're trying to do (in high-level, non-tehcnical terms) we can probably show you the best-of-breed design pattern.

<?php

// SET A COOKIE, ...
// BUT FOR WHAT SUBDOMAINS?
// AND WHAT PATH?
// HOW LONG SHOULD THE COOKIE LIVE?
// SHOULD IT BE VISIBLE TO JAVASCRIPT OR NOT?
setcookie("ticker",'testing');

// IF THIS COOKIE ALREADY EXISTED BEFORE THIS HTTP REQUEST
if (isset($_COOKIE['ticker'])) { 
/* ticker cookie is set  so do other php code here */
 }

// IF THIS COOKIE DID NOT ALREADY EXIST BEFORE THIS HTTP REQUEST
// MISSING STATEMENT TERMINATOR CAUSES A PARSE ERROR;
 else header("location:main.php"]
 
// THE SCRIPT WILL NEVER GET TO THIS INSTRUCTION BECAUSE IF/ELSE WILL STOP IT
?>
<html>
<body>
</body>
......code html here
</html>

Open in new window

duncanb7

ASKER

Thanks Ray's rely even the question is closed.

For my memo only:
Finally, I decided to separate the code into two php pages or files.
One php page is resolved all cookie or seesion issue first , and becoz it is
really small file size so it won't create too long http request time.
The second one is main php page for larger file html code and size that is redirected
in the first php page by header(). That I think it will help on double request loading time issue.

Have a nice day

Duncan

first.php (the first php file)
======================

<?php 
$path=str_ireplace($_SERVER['DOCUMENT_ROOT'], '', dirname($_SERVER['SCRIPT_FILENAME']));
setcookie("ticker","testing", time()+3600*8, $path."/", $_SERVER["HTTP_HOST"], 0,1);
if (isset($_COOKIE['ticker'])) { 
header("location:second.php"); 
} 
else {
header("location:first.php")
;}
?>

Open in new window