I know the problem of "headers already sent" when trying to redirect after readfile. My question is how to handle such a situation so I get the website focus back or redirect to other website. I've created a simple example of what I'm dealing with. I've created a form and after the user gives a name and an email address, he can download a file, but after I can't do other things or redirect to other url. I can't find a way and think of a solution how should I rewrite my script and create things in proper way. How these download forms should be build in a right way?
<body>
<?php
$errors = [];
$name = "";
$email = "";
if (isset($_POST["submit"])) {
$name = htmlspecialchars(stripslashes(trim($_POST["name"])));
$email = htmlspecialchars(stripslashes(trim($_POST["email"])));
if(!preg_match("/^[A-Za-z .'-]+$/", $name)){
$errors[] = "Invalid name";
}
if(!preg_match("/^[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}$/", $email)){
$errors[] = "Invalid email";
}
if (empty($errors)) {
$file = "files/live.pdf";
header('Content-Description: File Transfer');
header('Content-Type: application/pdf');
header('Content-Disposition: attachment; filename=' . basename($file));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
ob_clean();
flush();
readfile($file);
echo "ok";
header("Location: http://something.com");
}
}
?>
<form method="POST">
<label for="name">Name</label>
<input type="text" id="name" name="name" value="<?= $name ?>" required><br>
<label for="email">Email</label>
<input type="email" id="email" name="email" value="<?= $email ?>" required><br>
<button type="submit" name="submit">Download</button><br>
</form>
<p>
<?php if (!empty($errors)) : ?>
<ul>
<?php foreach ($errors as $error) : ?>
<li><?= $error ?></li>
<?php endforeach; ?>
</ul>
<?php endif; ?>
</p>
</body>
