I'm developing a simple member management system with php, and I've met a problem:
The user logs in and it is redirected to a main page and the user ID is saved in the session; there are some links to other pages in the main page, after the user clicks and is trying to go back to main by pressing browser "Back" button, sometimes the user ID in the session is lost.
I've checked the session save path, a new session file is created when I click "Back" button, so I assume the session_start() creates a new session for it; but I still don't know why, it's a random case...
Is there any way to solve it?
main.php:
<?php session_start(); ?>
<?php
$echo_string = '
<body>
<a href="a.php">a</a>
<a href="b.php">b</a>
</body>';
if (!empty($_SESSION['user']))
echo $echo_string;
else
header("Location: login.php");
?>
login.php:
<?php
session_start();
if (isset($_POST['userLogin'])) {
$_SESSION['user'] = $_POST['userLogin'];
...
}
header("Location: main.php");
?>
<form novalidate="" method="post" action="login.php">
<label class="hidden-label" for="Username">Username</label>
<input id="Username" name="userLogin" type="text" placeholder="Username" value="" spellcheck="false" class="">
<label class="hidden-label" for="Passwd">Password</label>
<input id="Passwd" name="userPassword" type="password" placeholder="Password" class="">
<input id="signIn" name="signIn" class="rc-button rc-button-submit" type="submit" value="Log in">
</form>
a.php and b.php:
<?php session_start(); ?>
<!DOCTYPE html>
<html lang="en">
<head>...</head>
<?php
$echo_string = '...';
if (!empty($_SESSION['user']))
echo $echo_string;
else
header("Location: login.php");
?>
</html>