How to Prevent Form Submissions from Being Repeated on Refresh?

Preventing Redundant Form Submissions on Refresh

In web application development, it's not uncommon to encounter situations where refreshing a page after form submission leads to unintended multiple submissions. This behavior can occur when the server-side code does not properly handle form submission processing.

Consider the following example where a form is intended to insert data into a database upon submission:

<?php
if (isset($_POST['name'])) {
    // Database operation to insert $_POST['name']
    echo "Operation Done";
    die();
}
?>

<form action='page.php' method='post' name="myForm">
    <input type="text" maxlength="50" name="name" class="input400" />
    <input type="submit" name="Submit" />
</form>

After submitting the form, the data is successfully inserted into the database and the message "Operation Done" is displayed. However, if the page is subsequently refreshed, the form submission is repeated, resulting in the data being inserted again.

Solution: Redirect After Successful Form Submission

To avoid this problem, it's essential to redirect to another page after successfully processing the form submission. This ensures that when the page is refreshed, it's the new page that is being loaded, not the same form submission page.

Example with Redirect:

<?php
if (isset($_POST['name'])) {
    // Database operation to insert $_POST['name']
    header('Location: /path/to/record');
    exit;
}
?>

By adding the header redirection, the code ensures that after the database operation is complete, a redirect occurs to a new path. If the user refreshes the page, they will be directed to the new path instead of the form submission page.

Benefits of Redirecting:

• Prevents redundant submissions: When a user refreshes the page after submission, they are no longer resubmitting the form.
• Clear user experience: The user sees a different page after the form is successfully submitted, providing a clear indication that the operation was completed.
• Improved usability: If the user had accidentally refreshed the page after the form was submitted, they wouldn't need to resubmit the form manually, reducing user frustration.

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