![]() ![]() If the session does not exist, the header() function is used to redirect the user back to login.php and prevents viewing of access.php contents. A script on access.php checks to ensure the session exists. The user is then redirected to access.php. Next, a session variable - access is created and assigned a value of "yes". The PHP script ensures that the password and user name are correct. After the user enters a valid username and password, the "Login" button is clicked. A session is created to ensure that the user is authenticated. Before a user can view the contents of access.php, they must pass login.php. The example above consists of two pages, login.php and access.php. This is accomplished by using session_destroy(). When the user exits or chooses to "log out", the session variable should be reset. In this case the session variable contains a value that is passed from page to page indicating that the user has permission to access any resources associated with the site. Session variables provide an ideal way of creating page counters since each user represents a unique session.Ī session variable may also be created after a user successfully enters the credentials needed to access a restricted site. In this case, the session variable count is used to count the number of visitors. Otherwise the value of the session varible is incremented by 1. If the session is null or contains no value, it is intialized to 1. Next, an if statement is used to check the value of the session variable "count". Session_start() must be called before creating and assigning values to session variables. In this example, session_start() is first called to intialize session data. The follow code block demonstrates how the session variable is intitalized. header("Location: ") - header function used redirect the browser page to the Location parameter provided.Although this is an HTTP function and not a session function, it is commonly used to redirect user's during existing sessions. This tutorial also introduces the PHP "Location" header() function. session_destroy() - destroys all data registered to a script's current session.This function is called prior to creating a new session variable using $_SESSION. session_start() - initializes session data.$_SESSION - PHP superglobal array variable that contains currently registered to a script's session.The Session functions session_start() and session_destroy() are also introduced. $_SESSION is recommended for improved security and code readability. This tutorial begins by introducing the $_SESSION global variable. PHP supports a number of custom session handlers. Each request for a page is completely independant of earlier requests, so if you want subsequent pages to "remember" the users name that he entered on your front page you have to store that information somewhere. The problem that Session variables have to overcome is that the HTTP protocol used to browse the web is stateless. using PHP functions such as session_destroy() to free all session variables currently registered. the maximum time allotment set on the server for session lifetime is exceeded 3. ![]() Session variables normally exist until one of the follow criteria is met: 1. With session variables, user-specific data can be preserved from page to page delivering customized content as the user interacts with the web application. A session variable is a special type of variable whose value is maintained across subsequent web pages. ![]()
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