Setting Session Variables and Calling them on Another Page - php

Question

I salute you all for your previous help.
Would anyone imagine this very simple error, which has put me down for a couple of hours.
From the Login Page, I compare (authenticate) the login username and password with the database values. If they match, I store them in session variables and redirect to the dashboard page.
Before redirection, I print_r ($_SESSION) to see whether the variables are set or not. They output was TRUE (session is set).
But on the dashboard, calling the session variables returned session !set.
Please check the following code.
[LOGIN PAGE]
<?php
session_start();
require_once('../data/conString_mysqli.php');
$uNameErr = $pWordErr = "";
$uName = $pWord = "";
if ($_SERVER["REQUEST_METHOD"] == "POST") {
//*************************************
if (!empty($_POST["username"])) {
$uName = test_input($_POST["username"]);
} else {
$uNameErr = "Email is required!";
// check if e-mail address is well-formed
if (!filter_var($uName, FILTER_VALIDATE_EMAIL)) {
$uNameErr = "Invalid email format";
}
}
if (!empty($_POST["password"])) {
$pWord = test_input($_POST["password"]);
$hashed = md5($pWord);
} else {
$pWord1Err = "Password is Required!";
if ($pWord < 8) {
$pWordErr = "Invalid Password.";
}
}
}//end if... IS_POST
function test_input($data) {
//require connection file
$data = trim($data);
$data = stripslashes($data);
$data = htmlspecialchars($data);
return $data;
}//end function
?>
<?php
if (!empty($uName) && !empty($pWord)){
$hashed = md5($pWord);
$read_data = mysqli_query($connect, "SELECT * FROM service_providers WHERE activated='1' AND ppword ='".$hashed."' AND pemail='".$uName."'") or die(mysqli_error());
$count = mysqli_num_rows($read_data);
if($count >= 1){/*echo '<script type="text/javascript">alert("Records Found!");</script>';*/
//store session variables
$row = mysqli_fetch_array($read_data);
$_SESSION[ 'serv_pid' ] = $row[ 'serv_pid' ];
$_SESSION[ 'providerName' ] = $row[ 'pname' ];
echo '<script type="text/javascript">alert("Session Name: '.$_SESSION['providerName']." - Session ID: ". $_SESSION['serv_pid'].'");window.location="../dashboard/";</script>';
/*echo "<pre>";
print_r ($_SESSION);
echo "</pre>";
*/
}else{echo '<script type="text/javascript">alert("Invalid Login Details");window.location="../login/";</script>';
}
}
?>
<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>" style="margin-top: 1.5em;">
<div class="form-group">
<div class="input-group">
<input type="text" name="username" class="form-control text-center" placeholder="username (your email)" value="<?php echo $uName;?>"><span class="error"> <?php echo $uNameErr;?></span>
<span class="input-group-addon btn btn-warning" style="background: #f0ad4e; color: #fff;">
<span class="glyphicon glyphicon-user" style="margin: 0;"></span>
</span>
</div>
</div>
<div class="form-group">
<div class="input-group">
<input type="password" name="password" class="form-control text-center" placeholder="password" value="<?php echo $pWord;?>"><span class="error"> <?php echo $pWordErr;?></span>
<span class="input-group-addon btn btn-warning" style="background: #f0ad4e; color: #fff;">
<span class="glyphicon glyphicon-lock" style="margin: 0;"></span>
</span>
</div>
</div>
<p style="font-size: 16px !important;"><a style="color: #fff; text-decoration: none; margin-top: 2em; display: block;" href="../sign-up/">Don't have an Account? <u>Get one!</u></a> <span style="color:#FF0000; font-weight:bold; text-decoration:underline;"><em>Forgot your password?</em></span></p>
<div class="col-md-6 col-md-offset-3 text-center" style="margin-top: 5px;">
<button type="submit" name="login" class="btn btn-warning btn-lg btn-custom" style="margin-right: 1em; border-width: 3px;">LOGIN</button>
SIGN UP
</div>
<div class="clearfix"></div>
</form>
[DASHBOARD PAGE]
<?php
session_start();
echo "<pre>";
print_r ($_SESSION);
echo "</pre>";
/*
if (!isset($_SESSION['serv_pid'])){// or !isset($_SESSION['providerName'])){
die('<script type="text/javascript">alert("You do not have permission to access beyond the previous page.");window.location="../login/";</script>');
}else{
$serv_pid = $_SESSION['serv_pid'];
$pName = $_SESSION['providerName'];
}*/
?>
From the Login Page, the result returned by print_r is:
Array
(
[serv_pid] => 1
[providerName] => No Name
)
But on getting to the login page, it's like the session is destroyed.
The result returned by print_r is:
Array
(
)
Please help me with any ideas.
Thank you in advance.

Answer 1

When you start a session in PHP, it sets a session cookie, that's sent to the browser when you print the first character outside php brackets or at your first echo.
I think the problem is when you try to redirect the user to the dashboard page. You're setting the session, writing to the browser a script that redirects to another page, but in the meanwhile the server doesn't stop the processing on the page.
Try replacing the echo "<script>..." with a header("Location: dashboard.php") in PHP, followed by a exit(0); instruction.
The first one actually tells the browser to redirect to the dashboard.php page (or whatever the page is), the second tells the browser to stop executing the page.
Moreover, delete the blank row between ?> and <?php brackets. That row actually sends the headers to the browser, along with cookies, even if it's a blank character.

Answer 2

There were excess session_start() functions on the landing page and on the sending page. Each session_start() cancelled the other and the variables were destroyed before getting to the landing page.
However, I had to drop the entire pages and recreate them one line at a time. So, it's working now.
I really want to appreciate Marco Todisco, who also contributed suggestive responses to assisting me on my coding.