Posts Tagged ‘cookie’
Tuesday, July 29th, 2008
The most common meaning of “Cookie” on the Internet refers to a piece of information sent by a Web Server to a Web Browser that the Browser software is expected to save and to send back to the Server whenever the browser makes additional requests from the Server. Depending on the type of Cookie used, and the Browsers’ settings, the Browser may accept or not accept the Cookie, and may save the Cookie for either a short time or a long time. Cookies might contain information such as login or registration information, online “shopping cart” information, user preferences, etc. When a Server receives a request from a Browser that includes a Cookie, the Server is able to use the information stored in the Cookie. For example, the Server might customize what is sent back to the user, or keep a log of particular users’ requests. Cookies are usually set to expire after a predetermined amount of time and are usually saved in memory until the Browser software is closed down, at which time they may be saved to disk if their “expire time” has not been reached. Cookies do not read your hard drive and send your life story to the CIA, but they can be used to gather more information about a user than would be possible without them. From Matisse
Tags: browser, cookie, down, information, particular, possible, predetermined, server, stored, story, time, Usually
Posted in Uncategorized, tricks | No Comments »
Tuesday, July 29th, 2008
The main difference between cookies and sessions is that cookies are stored in the user’s browser, and sessions are not. This difference determines what each is best used for.
A cookie can keep information in the user’s browser until deleted. If a person has a login and password, this can be set as a cookie in their browser so they do not have to re-login to your website every time they visit. You can store almost anything in a browser cookie. The trouble is that a user can block cookies or delete them at any time. If, for example, your website’s shopping cart utilized cookies, and a person had their browser set to block them, then they could not shop at your trouble .
Sessions are not reliant on the user allowing a cookie. They work instead like a token allowing access and passing information while the user has their browser open. The problem with sessions is that when you close your browser you also lose the session. So, if you had a site requiring a login, this couldn’t be saved as a session like it could as a cookie, and the user would be forced to re-login every time they visit.
You can of course get the best of both worlds! Once you know what each does, you can use a combination of cookies and sessions to make your site work exactly the way you want it to.
Tags: browser, combination, cookie, cookies, determines, exactly, forced, Instead, once, sessions, trouble
Posted in Uncategorized, tricks | No Comments »
Monday, July 14th, 2008
It’s a proven fact that the use of popup windows is an effective marketing technique that produces great results. However, they can be very irritating to your visitors. How can you use this powerful marketing technique without offending your visitors? Compromise and use a popup window that only displays the first time your visitor enters your site.
Place the following code within the <BODY> of your web page.
<SCRIPT LANGUAGE=”JavaScript”>
<!–
function GetCookie(name) {
var arg=name+”=”;
var alen=arg.length;
var clen=document.cookie.length;
var i=0;
while (i<clen) {
var j=i+alen;
if (document.cookie.substring(i,j)==arg)
return “here”;
i=document.cookie.indexOf(” “,i)+1;
if (i==0) break;
}
return null;
}
var visit=GetCookie(”COOKIE1″);
if (visit==null){
var expire=new Date();
window.name = “thiswin”;
newwin=open(”yourpage.htm”, “dispwin”,
“width=450,height=455,scrollbars=yes,
menubar=no”);
expire=new Date(expire.getTime()+7776000000);
document.cookie=”COOKIE1=here; expires=”+expire;
}
// –>
</SCRIPT>
Change the text where indicated in red.
The “yourpage.htm” text specifies the popup window url.
Change the height and width to your preferred window size.
Tags: Add new tag, body, cookie, creating, Effective, First, irritating, Javascript, language, length, Open, Pop-Up, powerful, produces, substring, technique, visitor enters, visitors, Web Page, Window
Posted in web designing | No Comments »
Monday, June 30th, 2008
Problem
Short expiry cookies depend on users having their system clocks set correctly.
Solution
Don’t depend on the users having their clocks set right. Embed the timeout based on your server’s
clock in the cookie.
<?php
$value = time()+3600 . ‘:’ . $variable;
SetCookie(’Cookie_Name’,$value);
?>
Then when you receive the cookie, decode it and determine if it is still valid.
<?php
list($ts,$variable) = explode(’:',$Cookie_Name,2);
if($ts < time()) {
…
} else {
SetCookie(’Cookie_Name’,”);
}
?>
Tags: clocks, cookie, Expiry, explode, PHP, problem, SetCookie, solution, timeout
Posted in PHP | No Comments »
Monday, June 30th, 2008
set_magic_quotes_runtime(FALSE);
if (get_magic_quotes_gpc()) {
/*
All these global variables are slash-encoded by default,
because magic_quotes_gpc is set by default!
(And magic_quotes_gpc affects more than just $_GET, $_POST, and $_COOKIE)
*/
$_SERVER = stripslashes_array($_SERVER);
$_GET = stripslashes_array($_GET);
$_POST = stripslashes_array($_POST);
$_COOKIE = stripslashes_array($_COOKIE);
$_FILES = stripslashes_array($_FILES);
$_ENV = stripslashes_array($_ENV);
$_REQUEST = stripslashes_array($_REQUEST);
$HTTP_SERVER_VARS = stripslashes_array($HTTP_SERVER_VARS);
$HTTP_GET_VARS = stripslashes_array($HTTP_GET_VARS);
$HTTP_POST_VARS = stripslashes_array($HTTP_POST_VARS);
$HTTP_COOKIE_VARS = stripslashes_array($HTTP_COOKIE_VARS);
$HTTP_POST_FILES = stripslashes_array($HTTP_POST_FILES);
$HTTP_ENV_VARS = stripslashes_array($HTTP_ENV_VARS);
if (isset($_SESSION)) { #These are unconfirmed (?)
$_SESSION = stripslashes_array($_SESSION, ”);
$HTTP_SESSION_VARS = stripslashes_array($HTTP_SESSION_VARS, ”);
}
/*
The $GLOBALS array is also slash-encoded, but when all the above are
changed, $GLOBALS is updated to reflect those changes. (Therefore
$GLOBALS should never be modified directly). $GLOBALS also contains
infinite recursion, so it’s dangerous…
*/
}
function stripslashes_array($data) {
if (is_array($data)){
foreach ($data as $key => $value){
$data[$key] = stripslashes_array($value);
}
return $data;
}else{
return stripslashes($data);
}
}
Tags: array, cookie, Default, Disable, effect, false, files, get, HTTP, magic, PHP, quotes, runtime, session, Slash (/), these, VARS
Posted in PHP | No Comments »
Monday, June 30th, 2008
<?php
setcookie(’myCookie’, ’some value’, time() + 60*15, ‘/’, ‘.mydomain.com’);
?>
Tags: cookie, Multiple, PHP, send, subdomains, Tips
Posted in PHP | No Comments »
Saturday, June 28th, 2008
‘Warning: Cannot modify header information - headers already sent by (output started at filename line no __) ‘
If you run a PHP document get the above error message, it means that an error has occured in your php document. This takes place if there are any executable statements like echo before the set cookie or session variable. Try to find the statement and remove it and then run the same program.
Tags: already, common, cookie, Document, error message, errors, headers, information, PHP, program, session, warning
Posted in PHP | No Comments »