Preventing form resubmission

Question

Page one contains an HTML form. Page two - the code that handles the submitted data.

The form in page one gets submitted. The browser gets redirected to page two. P

Answer 1

The PRG pattern can only prevent the resubmission caused by page refreshing. This is not a 100% safe measure.

Usually, I will take actions below to prevent resubmission:

1. Client Side - Use javascript to prevent duplicate clicks on a button which will trigger form submission. You can just disable the button after the first click.

2. Server Side - I will calculate a hash on the submitted parameters and save that hash in session or database, so when the duplicated submission was received we can detect the duplication then proper response to the client. However, you can manage to generate a hash at the client side.

In most of the occasions, these measures can help to prevent resubmission.