|
|
|
|
|
|
 |
|
|
Displaying 1 to 1 (of 1 messages) |
Page 1 of 1 |
| Forums |
Sarun kumar |
| PHP Session |
| Last Post : 05th Dec, 2011 |
$_SESSION is a special array used to store information across the page requests a user makes during his visit to your website or web application. The most fundamental way to explain what a sessions is like is to imagine the following scenario:
You are working with an application. You open it, make some changes, and then you close it.
That is a session in it’s simplest form.
The example scenario is reminiscent of the process that happens when using a login system. The process can be extremely complicated or incredibly simple, as long as there is a value that persists between requests. Information stored in the session can be called upon at any time during the open session.
While there may be many users accessing the site at the same time, each with his own session, it’s thanks to unique IDs assigned and managed by PHP for each session that allows each user’s session to be available only to himself. Session information is stored on the server rather than the user’s computer (as cookie data is stored), which makes sessions more secure than traditional cookies for passing information between page requests.
In this article I’ll give you the low down on using sessions in PHP – how to create them, how to destroy them, and how to make sure they remain secure.
Using Sessions
Before you can to store information in a session, you have to start PHP’s session handling. This is done at the beginning of your PHP code, and must be done before any text, HTML, or JavaScript is sent to the browser. To start the session, you call the session_start() function in your first file:
1
2
// start them engines!
3
session_start();
4
// store session data
5
$_SESSION["username"] = "Callum";
session_start() starts the session between the user and the server, and allows values stored in $_SESSION to be accessible in other scripts later on.
In your second file, you call session_start() again which this time continues the session, and you can then retrieve values from $_SESSION.
1
2
// continue the session
3
session_start();
4
// retrieve session data
5
echo "Username = " . $_SESSION["username"];
This example is a very basic demonstration of storing and retrieving data in a session. In the first script, the value “Callum” was associated with the key “username” in the $_SESSION array. In the second script, the information was requested back from the $_SESSION array using the key. $_SESSION allows you to store and retrieve information across the page requests of a user’s active browsing session.
Ending a Session
As important as it is to begin a session, so it is to end one. Even though a session is only a temporary way to store data, it is very important to clean up after yourself to ensure maximum security when dealing with potentially sensitive information. It is also good practice and will avoid having a huge amount of stale session data sitting on the server.
To delete a single session value, you use the unset() function:
1
2
session_start();
3
// delete the
| |
| |||
|
|
|
Hits : 121 |
|
|
|
|
|
|
|
