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Page created 8 May 2005, updated 13 June 2008.

PHP Programming

Page 3

This article is about using cookies with PHP.

COOKIE PROBLEMS

It's easy to create a Cookie, but if you use comas, semi-colons, or white spaces, you will have to 'escape' the characters. In reality, you will probably collect the data from a form, and somebody is bound to enter a character, which needs to be escaped. Therefore, it makes sense to always escape the cookie data.

ENCODE AND DECODE

To escape a string you use the ' rawurlencode() ' function. This is the equivalent to the 'Escape' function in JavaScript. To restore the data, you use the ' rawurldecode ' function.

CREATING A COOKIE

At the time, I thought it would be a good idea to use a 'Function' to encode the string. The idea being that I might want to use the function for another script. The script uses 3 strings, $name, $address, $mail, and separates them with '||', before combining them into $str.

<?php

//==================================== Encoder

function encode( $str ){

$res=rawurlencode($str);

return $res;

}

//======================================= Set variables

$name = "My Name";

$address = "My Address";

$mail = "jim@daftwat.biz";

//================================================ Create Cookie

$str = $name . "||" . $address . "||" . $mail;

$code = encode( $str );

setcookie( "cook1", $code );

?>

RESTORING THE DATA

The script below returns the data from the cookie, back to the original strings, $name, $address, and $mail.

<?php

//=================================== Decoder

function decode( $str ){

$res = rawurldecode( $str );

return $res;

}

//======================================== Get cookie

$code1 = $_COOKIE['cook1'];

$code2 = decode( $code1 );

//=================================== Create array

$code3 = split( "[||]" , $code2 );

//===================================== Restore original data

$code3[0] = $name;

$code3[1] = $address;

$code3[2] = $mail;

//================================ Print values

echo( $name . "<br>" );

echo( $address . "<br>" );

echo( $mail . "<br>" );

?>

NOTES

In case you're wondering why I used '||' to separate the strings, my reasoning is that it is very unlikely that somebody would enter "||" into a form field. If they do, it will create an extra string, and create an error. I dare say that some idiot will read this and start typing "||" into every form on the Internet. What ever you do, don't vote for him (could it possibly be a girl?).

The cookie is set to last for the session only. If you want it to remain, you will have to set the date. For example:

setcookie( "cook1", $code, time() + 36000 );

JAVASCRIPT

Since all programming languages are similar, I decided to create a similar script using JavaScript. It is located, of course, in the JavaScript section.