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[SOLVED] Using Session Control in PHP part2

Trium918

By Trium918
in PHP Coding Help

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Trium918 Advanced Member

Trium918

Posted
Posted

Simple Session Example part2

 

I implemented a set of 3 pages.

<?
session_start();
//authmain.php
if ($_POST['username'] && $_POST['password'])
{
  // if the user has just tried to log in
  
    // register_global = Off
  // inside the php.ini configuration file
  $username = stripslashes($_POST['username']);
  $password = stripslashes($_POST['password']);

  // Connect to MySql
  $db = mysql_connect("localhost") or die(mysql_error());

  // Select the appropriate database
  mysql_select_db("member_auth",$db) or die(mysql_error());
  
  $query = "SELECT * FROM user_info_auth WHERE
		username ='$username' AND 
		password ='$password' ";

  $result = mysql_query($query);
  if (mysql_num_rows($result) >0 )
  {
    // if they are in the database register the user id
    $valid_user = $username;
    session_register("valid_user");
  }
}
?>
<html>
<body>
<h1>Home page</h1>
<? 

  if (session_is_registered("valid_user"))
  {
    echo "You are logged in as: $valid_user <br>";
    echo "<a href=\"logout.php\">Log out</a><br>";
  }
  else
  {
    if (isset($username))
    {
      // if they've tried and failed to log in
      echo "Could not log you in";
    }
    else 
    {
      // they have not tried to log in yet or have logged out
      echo "You are not logged in.<br>";
    }

    // provide form to log in 
    echo "<form method=post action=\"authmain.php\">";
    echo "<table>";
    echo "<tr><td>Username:</td>";
    echo "<td><input type=text name=username></td></tr>";
    echo "<tr><td>Password:</td>";
    echo "<td><input type=password name=password></td></tr>";
    echo "<tr><td colspan=2 align=center>";
    echo "<input type=submit value=\"Log in\"></td></tr>";
    echo "</table></form>";
  }
?>
<br>
<a href="members_only.php">Members section</a>
</body>
</html>

 

<?
  //members_only.php
  
/*The output to this should be
echo "<p>You are logged in as $valid_user.</p>"; but
valid_user looses it value*/

  session_start();

  echo "<h1>Members only</h1>";

  // check session variable

  if (session_is_registered("valid_user"))
  {
    echo "<p>You are logged in as $valid_user.</p>";
    echo "<p>Members only content goes here</p>";
  }
  else
  {
    echo "<p>You are not logged in.</p>";
    echo "<p>Only logged in members may see this page.</p>";
  }

  echo "<a href=\"authmain.php\">Back to main page</a>";
?>

 

// logout.php
<?
  session_start();

  $old_user = $valid_user;  // store  to test if they *were* logged in
  $result = session_unregister("valid_user");
  session_destroy();
?>
<html>
<body>
<h1>Log out</h1>
<? 
  if (!empty($old_user))
  {
    if ($result)
    { 
      // if they were logged in and are not logged out 
      echo "Logged out.<br>";
    }
    else
    {
     // they were logged in and could not be logged out
      echo "Could not log you out.<br>";
    } 
  }
  else
  {
    // if they weren't logged in but came to this page somehow
    echo "You were not logged in, and so have not been logged out.<br>"; 
  }
?> 
<a href="authmain.php">Back to main page</a>
</body>
</html>

 

I am using old coding techniques, so could

someone please bring me up to date.

wildteen88 Regular Member

wildteen88

Posted
Posted

We are not here to code/recode stuff for you. But here is some tips:

 

If you see anything like this:

$valid_user = $username;
    session_register("valid_user");

 

Then change it to:

$_SESSION['valid_user'] = $username;

 

if you see session_unregister("valid_user");

 

use unset($_SESSION['valid_user']);

 

If you see $valid_user change it to $_SESSION['valid_user']

kenrbnsn Regular Member

kenrbnsn

Posted
Posted

Do not use the functions session_register, is_session_registered, and session_unregister. You want to explicitly set the session variable, test the session variable unset the session variable. Therefore your first program becomes:

<?php
session_start();
//authmain.php
if ($_POST['username'] && $_POST['password'])
{
  // if the user has just tried to log in
  
    // register_global = Off
  // inside the php.ini configuration file
  $username = stripslashes($_POST['username']);
  $password = stripslashes($_POST['password']);

  // Connect to MySql
  $db = mysql_connect("localhost") or die(mysql_error());
  // Select the appropriate database
  mysql_select_db("member_auth",$db) or die(mysql_error());
  
  $query = "SELECT * FROM user_info_auth WHERE username ='$username' AND password ='$password' ";
  $result = mysql_query($query);
  if (mysql_num_rows($result) >0 )
  {
    // if they are in the database register the user id
    $valid_user = $username;
    $_SESSION['valid_user'] = $valid_user; // instead of session_register("valid_user");
  }
}
?>
<html>
<body>
<h1>Home page</h1>
<? 
  if (isset($_SESSION['valid_user'])) // instead of if (session_is_registered("valid_user"))
  {
    echo "You are logged in as: $valid_user <br>";
    echo "<a href=\"logout.php\">Log out</a><br>";
  }
  else
  {
    if (isset($username))
    {
      // if they've tried and failed to log in
      echo "Could not log you in";
    }
    else 
    {
      // they have not tried to log in yet or have logged out
      echo "You are not logged in.<br>";
    }

    // provide form to log in 
    echo "<form method=post action=\"authmain.php\">";
    echo "<table>";
    echo "<tr><td>Username:</td>";
    echo "<td><input type=text name=username></td></tr>";
    echo "<tr><td>Password:</td>";
    echo "<td><input type=password name=password></td></tr>";
    echo "<tr><td colspan=2 align=center>";
    echo "<input type=submit value=\"Log in\"></td></tr>";
    echo "</table></form>";
  }
?>
<br>
<a href="members_only.php">Members section</a>
</body>
</html>

 

Your second script becomes:

<?php
session_start();  // session_start MUST be place before any output
  //members_only.php
  
/*The output to this should be
echo "<p>You are logged in as $valid_user.</p>"; but
valid_user looses it value*/


  echo "<h1>Members only</h1>";

  // check session variable

  if (isset($_SESSION['valid_user']))
  {
    echo "<p>You are logged in as $valid_user.</p>";
    echo "<p>Members only content goes here</p>";
  }
  else
  {
    echo "<p>You are not logged in.</p>";
    echo "<p>Only logged in members may see this page.</p>";
  }

  echo '<a href="authmain.php">Back to main page</a>';
?>

 

And your third script:

<?php
  session_start();

  $old_user = $_SESSION['valid_user'];  // store  to test if they *were* logged in
?>
<html>
<body>
<h1>Log out</h1>
<? 
  if (isset($_SESSION['valid_user']))
  {
     unset($_SESSION['valid_user']); // instead of $result = session_unregister("valid_user");
     session_destroy();
      echo "Logged out.<br>";
  } else  // if they weren't logged in but came to this page somehow
    echo "You were not logged in, and so have not been logged out.<br>"; 
?> 
<a href="authmain.php">Back to main page</a>
</body>
</html>

 

Ken

Trium918 Advanced Member

Trium918

Posted
  • Author
Posted

Would it be a good idea to initialize $_SESSION['valid_user'] = $valid_user;

on each page like in authmain because for some reason the session looses it

value with I click on the <a href=members_only.php>Membes Only</a>

link. I mean, echo "<p>You are logged in as $valid_user.</p>"; isn't showing

up. What would cause this?

Trium918 Advanced Member

Trium918

Posted
  • Author
Posted

I got it working, but is this a good way?

[qoute]

  if (isset($_SESSION['valid_user'])) // instead of if (session_is_registered("valid_user"))
  {
    echo "You are logged in as: $valid_user <br>";
    echo "<a href=\"logout.php\">Log out</a><br>";
  }

//change to:

if (isset($_SESSION['valid_user'])) // instead of if (session_is_registered("valid_user"))
  {
    echo "You are logged in as: ".$_SESSION['valid_user']."<br>";
    echo "<a href=\"logout.php\">Log out</a><br>";
  }

wildteen88 Regular Member

wildteen88

Posted
Posted

The latter code is correct:

if (isset($_SESSION['valid_user'])) // instead of if (session_is_registered("valid_user"))
  {
    echo "You are logged in as: ".$_SESSION['valid_user']."<br>";
    echo "<a href=\"logout.php\">Log out</a><br>";
  }

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