Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function split() is deprecated in /home3/vvaswani/public_html/community/columns/trog/article.php on line 101

Deprecated: Function eregi_replace() is deprecated in /home3/vvaswani/sql.php on line 301

Deprecated: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in /home3/vvaswani/public_html/community/columns/trog/article.php on line 107

Deprecated: preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead in /home3/vvaswani/public_html/community/columns/trog/article.php on line 109

Deprecated: Function ereg_replace() is deprecated in /home3/vvaswani/public_html/community/columns/trog/article.php on line 124

Deprecated: Function ereg_replace() is deprecated in /home3/vvaswani/public_html/community/columns/trog/article.php on line 125

Deprecated: Function split() is deprecated in /home3/vvaswani/public_html/community/columns/trog/article.php on line 127

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174

Deprecated: Function ereg() is deprecated in /home3/vvaswani/db-mysql.php on line 174
The Melonfire Community - Trog
Logo         Community
  Trog
Services
The Company
Community
Columns
Your Account
Contact Us
 
 
Using Cookies With JavaScript
Store and retrieve persistent data with cookies in JavaScript

| Caveat Emptor |

Before you start using cookies, there are a few things you should be aware of:

* Cookie technology has been supported correctly since Netscape Navigator 2.0. Internet Explorer users should, however, only use cookie technology on platforms supporting Internet Explorer 4.0 or better, due to errors in the cookie-handling routines of earlier versions.

* Since cookies are stored on the user's hard drive, you as the developer have very little control over them. If a user decides to turn off cookie support in his or her browser, your cookies will simply not be saved. Therefore, if data persistence is an important feature of your Web site, have a backup plan (such as server-side cookies or sessions) ready as well.

* A single domain cannot set more than twenty cookies. A single cookie cannot exceed 4 KB in size. The maximum number of cookies that may be set is 300.

Now, with the caveats out of the way, let's take a look at the ingredients that make up a cookie.

1. The first element in a cookie is a "name" attribute. Here, the "name" is a string used to identify the cookie (akin to a variable name), followed by the data to be stored in the cookie. This variable-value pair is required; you can't bake a cookie without it. For example,


email=me@some.domain.com


2. A cookie can also contain an "expires" attribute, which specifies how long the cookie is valid for. For example,


expires=Fri, 30-Jan-2004 12:00:00 GMT


Setting this element to a date in the past will usually cause the browser to delete the cookie.

3. You can also add a "path" attribute to a cookie - this states where the cookie may be accessed from on the Web site. Most often, this is set to the server's document root


path=/


to ensure that the data in the cookie is available to all the scripts on the site.

4. The "domain" attribute allows you to set a domain name for the cookie. Again, this is optional, and might look like this:


domain=somedomain.com


5. Finally, the "secure" attribute is a Boolean flag indicating whether a secure HTTP connection is required between the client and server to read the data in the cookie. Usually, this is toggled off.

As noted previously, only the first attribute is required; the rest are all optional. If you're using them, remember to separate them with semi-colons, as in the example below:


document.cookie = "name=Joe; path=/; domain=my.site.com; secure";


Now, let's look at writing some code to create a cookie.


How to do Everything with PHP & MySQL
How to do Everything with PHP & MySQL, the best-selling book by Melonfire, explains how to take full advantage of PHP's built-in support for MySQL and link the results of database queries to Web pages. You'll get full details on PHP programming and MySQL database development, and then you'll learn to use these two cutting-edge technologies together. Easy-to-follow sample applications include a PHP online shopping cart, a MySQL order tracking system, and a PHP/MySQL news publishing system.

Read more, or grab your copy now!


previous page more like this  print this article  next page
 
Search...
 
In trog...
Logging With PHP
Building A Quick-And-Dirty PHP/MySQL Publishing System
Output Buffering With PHP
Date/Time Processing With PHP
Creating Web Calendars With The PEAR Calendar Class
more...
 
In the hitg report...
Crime Scenes
Animal Attraction
Lord Of The Strings
more...
 
In boombox...
Patience - George Michael
Think Tank - Blur
My Private Nation - Train
more...
 
In colophon...
Hostage - Robert Crais
The Dead Heart - Douglas Kennedy
Right As Rain - George Pelecanos
more...
 
In cut!...
American Chai
The Core
Possession
more...
 
Find out how you can use this article on your own Web site!


Copyright © 1998-
Strict Standards: mktime(): You should be using the time() function instead in /home3/vvaswani/public_html/community/columns/trog/article.php on line 731
2018 Melonfire. All rights reserved
Terms and Conditions | Feedback