Mumbai University > Information Technology > Sem 4 > Web Programming

Marks: 10M

Year: May 2014, Dec 2014, May 2015 , Dec 2015

• When a user logs in to a application, performs some activity and close the application, this entire scenario is called as session.
• A web server needs to track all the activities of users. It needs to store required information about the user. This whole process is called as session tracking.
• There exists a session array which often stores the unique session ID for the session.
• PHP keep tracks of session by using a function called session_start().
• When session_start() function is invoked , session ID is created and recorded.

Following is a PHP code:

<?php
session_start();
if(isset($_SESSION[‘PGVISIT’]))
    {
    $_SESSION[‘PGVISIT’])=$_SESSION[‘PGVISIT’])+1;
    echo “You are visiting this page for:”$_SESSION [‘PGVISIT’])” times”;
}
else
{
echo “You are visiting this page for the first time”;
}
?>

• Another way to store information is using Cookies. Cookies is a small file that server embeds in a user’s machine.
• Cookies are used to identify users. It consists of a name and textual value. It can be created by some software system on the server.
• In every HTTP communication between browser and server, a header is included.

• The header part contains the information stored in cookies, about the message. -- In PHP, a function setcookie() can be used to create cookie.

  <?php
  $Cookie_period=time()+60*60*24*30;
          setcookie(“Myname”,”Alia”,$Cookie_period);
  ?>
  

• An information from the cookie can be retrieved in a following way:

   <?php
   if(isset($_COOKIE[“Myname”])
       echo “Welcome” .$_COOKIE[“Myname”].”….!!”;?>