Object Oriented Programming with PHP: Refreshing Kills my Objects

I have been poking around in PHP for OOP and I noticed something... Objects are re-instantiated each time the page is refreshed. The problem is that I want the object to keep certain information in class variables for the whole time that someone is on a website.

1. Is there some sort of way to keep an object alive the whole time that someone is surfing on the website?
2. What alternatives are there to my problem?

It would be really helpful t开发者_运维问答o have example too!

You can use Sessions to keep data associated to one user between different pages (quoting) :

Session support in PHP consists of a way to preserve certain data across subsequent accesses.

See the Session Handling section of the manual, for more informations about sessions.

PHP isn't stateful. Every page load is a one time event. You can persist data with sessions, or by storing information in a database.

A php script has to exit before apache can serve the page, so if you really want to do that, one thing you can do is serialize and store all the objects that you want to persist and use session cookies to keep track of the users

1. PHP isn't statefull every request is a new process on the server

Your best bet is to use session data and hand the session data to the objects when you instantiate them. Have the contructors pull the data they need out of the session, and you'll essentially have the state fullness you need.

you can acess sesion using

$_SESSION['stuff'] = $data;

then you can use your objects like $x = new DataStore($_SESSION['stuff']);

if theres data in the session the object will populate itself from that data. Otherwise it will default to its standard init.

Even when approaches like serializing objects and then deserializing them is useful, you have to make sure you understand first why your objects "disappear".

HTTP, the protocol used to retrieve pages and other resources from Web servers, is stateless. It basically means one request knows nothing from another request, even when it came from the same user. Think of it this way, when you request your PHP page, the script is run and after it finishes Apache sends out the result to you. When you request the page again, it does the same thing as if it was the very first time you did it. It's stateless.

There are techniques to keep state between requests (make it to not forget your objects) and those involve things like cookies or URL rewriting. But you have to keep in mind the stateless nature of HTTP (and thus your PHP script) when developing Web applications.

SESSIONS are good, i use them to hold object state in some of my PHP programming.

Or a better solution would be to use Flex so you don't have to worry about the stateless HTTP protocol...