What are some best practices for handling form submissions in PHP to avoid issues like the one described in the forum thread?

Issue: One common issue with form submissions in PHP is the possibility of resubmitting the form data if the user refreshes the page after submitting the form. This can lead to duplicate entries in a database or unintended actions being performed. To avoid this issue, one solution is to use the POST/Redirect/GET pattern, where the form data is processed, and upon successful submission, the user is redirected to a different page using the GET method.

if ($_SERVER["REQUEST_METHOD"] == "POST") {
    // Process form data
    // Redirect to a different page after processing
    header("Location: success.php");
    exit;
}