Cookie preferences: Manage site user preferences stored in cookies

Don't let the name fool you, cookie_preference is merely an API
aimed at allowing you, the web developer, to easily implement
user preferences (either directly, or indirectly) as quickly
as possible. To do this I've developed this class, and even tested
it on my own shopping cart.

It's not a very complex script to implement, and it's error
handling is at a minimum, allowing you the developer to be more
elequent. If a preference can not be set, read, or whatever,
the class will just output a PHP Notice, which can be turned
off in your app by using error_reporting(E_ALL & ~E_NOTICE).

API Reference:

void cookie_preference ( [preference_name[, cookie_expiry[, cookie_secure[, rot13]]]] )

Description:
	Yes, this is the contructor, but it is worth mentioning
	because you can set up your default environment by passing
	certain arguements when creating your class object.
	
	preference_name is the name of the cookie that holds your preferences.
	cookie_expiry is the length of time you want your cookie to live.
	cookie_secure is for when setting secure cookies over HTTPS.
	rot_13 is to obfuscate your cookie using the rot13 encoding (has automatic support for PHP <4.2.0)

Example:
	$prefs = new cookie_preferences("my_prefs", time()+3600, 1, true);

bool preference_new ( preference_name, preference_value )

Description:
	Sets a new preference to your cookie, but only if it doesn't already exist. Returns
	TRUE on success, or FALSE on failure.

Example:
	if ($prefs->preference_new('foo', 'bar') === FALSE)
	{
		trigger_error("Preference foo already exists");
	}

bool preference_update ( preference_name, preference_value )

Description:
	Updates an already existing cookie with a new value.

Example:
	if ($prefs->preference_update('foo', 'bar') === FALSE)
	{
		trigger_error("Could not update preference foo");
	}

string preference_get ( preference_name )

Description:
	Returns the value of preference_name on success, and FALSE on failure.

Example:
	if (($foo = $prefs->preference_get('foo')) == FALSE)
	{
		trigger_error("Could not read preference foo");
	}

Bug reports, suggestions, or even patches should be sent to me directly,
so I can keep up with any and all development. Remember, if someone forks
the code--and you use their fork--and it doesn't work; I can't help you.
But, if you do use my code, and need any help (or whatever), you can shoot
me an email at phpclasses (at) kennethpaul (dot) com. Happy coding! :)