How can PHP scripts be designed to call themselves for form validation and submission, redirecting only if validation is successful?

To design PHP scripts that call themselves for form validation and submission, you can check if the form has been submitted using $_SERVER['REQUEST_METHOD'] == 'POST'. If validation fails, display error messages. If validation is successful, process the form data and redirect to another page using header('Location: newpage.php'). This way, the script will only redirect if validation is successful. 

<?php
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    // Perform form validation
    $errors = array();

    // If validation fails, display error messages
    if (/* validation fails */) {
        $errors[] = "Error message";
    } else {
        // Process form data
        // Redirect only if validation is successful
        header('Location: newpage.php');
        exit();
    }
}
?>

<!-- HTML form -->
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
    <!-- Form fields -->
    <input type="text" name="name">
    <!-- Submit button -->
    <input type="submit" value="Submit">
</form>

Keywords

PHP form validation form submission self-calling redirection

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