How to Prevent Form Resubmission on PHP Pages?

Preventing Form Resubmission on PHP Pages

When working with PHP pages that include form elements, it is crucial to address the issue of preventing form resubmission upon page refresh. This is especially important if the pages contain insert functions that should only execute once.

The Post-Redirect-Get Pattern

The recommended solution is to employ the Post-Redirect-Get (PRG) pattern. This involves the following steps:

1. Accept a POST request: The form data is received in a POST request.
2. Process the data: The data is processed, and the appropriate action (e.g., inserting data) is performed.
3. Issue a redirect response: A 303 "See Other" redirect response is issued to a new URL.
4. Accept a GET request: The browser will make a new GET request to the redirected URL.
5. Issue a 200 response: The server responds with a 200 "OK" status code and displays the page.

Handling Form Data Display

If you need to display data from the submitted form in the redirected page, consider including a unique identifier (e.g., a row ID) in the query string of the redirect URL. This allows you to retrieve the processed data from the database when the GET request is made.

The above is the detailed content of How to Prevent Form Resubmission on PHP Pages?. For more information, please follow other related articles on the PHP Chinese website!